Qur’anic Root Q S Ṭ S — Qisṭās: The Balance, Accurate Weighing, and Fair Measure in Trade
Qur’anic and lexical forms
1. Word Meaning and Structure
Arabic qisṭās (قِسْطَاس) denotes a balance or instrument for weighing things. Early usage particularly connects it with an accurate, reliable balance; some sources also use it for justice and correctness in measurement.
Qisṭās occurs twice in the Qur’an, both times with the verb wa-zinū and the adjective al-mustaqīm. Its Qur’anic use therefore concerns weighing and maintaining accuracy in measurement.
Al-ʿAyn, among the earliest comprehensive Arabic lexicons, explains both al-qisṭās and al-qusṭās through aqwamu al-mawāzīni (أَقْوَمُ الْمَوَازِينِ): the most accurate and sound of balances.
Lisān al-ʿArab likewise gives al-qisṭāsu wa-l-qusṭāsu: aʿdalu al-mawāzīni wa-aqwamuhā (القِسْطَاسُ وَالقُسْطَاسُ: أَعْدَلُ الْمَوَازِينِ وَأَقْوَمُهَا): a balance that weighs accurately and fairly.
Lisān al-ʿArab: balance, shāhīn, and qabbān
These definitions bring together the weighing instrument and the accuracy of its result.
A balance compares and measures weight. Merely possessing one does not guarantee accurate measurement: it may be faulty, poorly adjusted, or tampered with, and its operator may also misuse it.
Arabic qisṭās has thus become connected with an accurate balance and fair measurement.
The instrument’s name should nevertheless remain distinct from its desired quality.
In direct use, qisṭās names a balance or weighing instrument. Accuracy and justice may characterize it or result from its proper use.
The distinction matters in the Qur’an, where both occurrences carry the separate adjective al-mustaqīm.
One should therefore not simply translate qisṭās as “justice” without explanation, removing the weighing instrument from the sentence.
Qur’anic morphology indexes Q S Ṭ S as quadriliteral. A borrowed historical origin nevertheless has considerable support.
Some lexicographers connect it with Q S Ṭ and justice; others consider it borrowed into Arabic from another language.
These positions require separate examination. Formal resemblance between qisṭās and qisṭ alone does not establish direct derivation.
2. Linguistic Forms and Historical Origins
Qisṭās and Qusṭās
Arabic has two familiar pronunciations:
Qisṭās with i on the q, and qusṭās with u.
Early lexicons record both.
Commenting on Al-Isrāʾ 17:35, Al-Ṭabarī says both pronunciations occur in recognized Qur’anic readings.
Al-Ṭabarī: the two pronunciations and readings
The reading in Forqan’s current text uses qisṭās with i.
The vowel difference does not change the meaning: both concern a balance or an instrument for accurate weighing.
The familiar plural is qasāṭīs (قَسَاطِيس).
Al-Miṣbāḥ al-Munīr and Al-ʿAyn: pronunciations, plural, and meaning
That plural does not occur in the Qur’an. Both verses instead use the singular with a preposition and the definite article: bi-l-qisṭāsi.
The nearby name qisṭār is also recorded: some lexicons apply it to a money changer or financial official, while some accounts explain it as a balance. It should therefore not simply be assumed a pronunciation variant of qisṭās.
Lisān al-ʿArab and lexical sources: qisṭār and money changing
Qur’anic study should retain the actual form qisṭās, examining nearby names only as historical and lexical evidence.
Qisṭās: Arabic or Arabized?
Early lexicographers held two principal views of its origin.
One regards qisṭās as Arabic, connected with qisṭ, justice.
The other derives the balance name from the language of the Romans—that is, a language used within the Roman cultural sphere of that period.
Al-Jawālīqī, transmitting Ibn Durayd, identifies qisṭās as the balance and as an Arabized Roman word.
Ibn Barrī: Al-Jawālīqī’s transmission from Ibn Durayd on borrowing
Mujāhid likewise associates the Qur’anic word with justice in the Roman language. Another report gives its meaning as the balance.
The difference need not indicate two wholly separate words. A reliable weighing instrument’s name may also become associated with fairness and justice in broader use.
That connection does not establish abstract justice as the original meaning, with the instrument name derived later.
Possible Greek and Aramaic Origins
Studies of historical Qur’anic vocabulary propose different routes by which qisṭās entered Arabic.
Ancient Greek had words connected with weighing, balances, and weighing officials that some scholars have compared with qisṭās.
Jeffery, for example, discusses proposed connections with ζυγοστασία, weighing; ξέστης, a measure; and δικαστής, a judge. These are competing hypotheses, rather than components of one established historical route.
Aramaic and Syriac also have forms resembling qisṭā for measure and measurement.
Some scholars propose transmission into Arabic through an Aramaic language.
Scholars do not agree on the precise source form or route.
In his study of foreign Qur’anic vocabulary, Arthur Jeffery reviews several Greek and Latin proposals, indicating phonological or historical difficulties with them.
He finds an Aramaic starting point useful, while identifying the final s as a difficulty in explaining the word’s history.
Arthur Jeffery: Qisṭās, pp. 238 and 239; competing proposals
A borrowing hypothesis consequently has important support, but the exact source language and transmission route remain uncertain.
This caution matters: resemblance between words in different languages alone does not determine the direction or historical sequence of borrowing.
Borrowing would not erase a word’s clear meaning in Qur’anic-era Arabic.
Qisṭās became established in Arabic and its syntax. Its Qur’anic meaning should therefore be understood through that Arabic usage and sentence context.
The Relationship with Qisṭ
Arabic qisṭ concerns a share, an allotted portion, and justice in distribution and judgment.
The Qur’an uses qisṭ, muqsiṭīn, and qāsiṭūn from triliteral Q S Ṭ, but their forms and uses differ.
Qisṭās resembles qisṭ in its letters and can also be semantically connected with justice in weighing.
The Qur’anic index nevertheless records them under separate entries: Q S Ṭ and Q S Ṭ S.
Lexicographers likewise do not agree on direct derivation of qisṭās from qisṭ.
The word should not be artificially divided into qisṭ and another independent component, extracting a separate meaning from each.
It is preferable to study qisṭās as an established weighing-instrument name, identifying its relationship with justice through linguistic usage and Qur’anic context.
3. Weighing Instruments and Early Arabic Evidence
A Balance or One Particular Type?
Lexicons record several explanations of qisṭās.
Some simply identify it as the balance.
Others equate it with qabbān, an instrument using a lever and a weight.
Others connect it with shāhīn, which can designate a beam or part of a balance.
In the account preserved in Tahdhīb al-Lughah, Al-Zajjāj explains qisṭās as a just balance, whether used for dirhams or other things.
This matters because it does not restrict qisṭās to a particular construction or size.
Early balances could differ in size and design.
Two-pan balances compared the weight of two objects. Other instruments had a weight moving along a beam, its position allowing weight to be determined.
The Metropolitan Museum of Art: a Byzantine steelyard and sliding weight
Small and large balances also served different commodities.
There is insufficient lexical reason to restrict Qur’anic qisṭās to one particular instrument type.
The verse itself does not specify the balance’s construction, number of pans, beam shape, or weight type.
“Balance” is consequently the more direct, suitable equivalent. Qabbān and shāhīn can be examined as historically reported examples.
A Witness from ʿAdī ibn Zayd
One important pre-Islamic Arabic poetic witness for qisṭās is a verse attributed to ʿAdī ibn Zayd al-ʿIbādī:
فِي حَدِيدِ القِسْطَاسِ يَرْقُبُنِي الْحَارِسُ
وَالْمَرْءُ كُلَّ شَيْءٍ يُلَاقِي
fī ḥadīdi al-qisṭāsi yarqubunī al-ḥārisu / wa-l-marʾu kulla shayʾin yulāqī
“In the iron of the qisṭās, the guard watches me; and a person encounters everything.”
The verse belongs to a poem describing captivity, bonds, and guarding.
Tahdhīb al-Lughah quotes the witness; Al-Layth tentatively explains ḥadīd al-qisṭās as the iron of the qabbān.
Al-Layth’s tentative gloss connects ḥadīd al-qisṭās with a qabbān’s iron. The gloss alone does not securely establish the precise poetic image.
Since the verse concerns captivity and bonds, it should not be treated as a direct account of market weighing without examining the full poetic construction.
Nor does it establish that every qisṭās must have been made of iron.
The witness clearly attests the name qisṭās in poetry and connects the phrase with iron and bonds. Identifying that iron specifically with a weighing instrument remains a tentative lexical explanation.
Lisān al-ʿArab: ʿAdī’s verse and Al-Layth’s tentative gloss
ʿAdī ibn Zayd was a pre-Islamic poet associated with al-Ḥīrah and Sasanian Iran’s cultural environment.
His use has historical significance, attesting the word’s presence in Arabic before Qur’anic revelation.
Presence in pre-Islamic poetry does not itself establish native Arabic origin. Loanwords can enter a language long before being recorded in a particular text, becoming natural in its poetry and speech.
Kitāb al-Jīm: another version of ʿAdī’s verse with textual variants
From the Physical Balance to a Criterion of Justice
A balance compares and determines weight.
When trading parties agree on an amount, a balance can establish its actual quantity.
A poorly adjusted balance or fraudulent operator, however, produces an incorrect measurement.
The semantic relationship between balances and justice is thus understandable.
Arabic mīzān likewise denotes a weighing instrument while extending to a criterion of assessment and justice.
Some lexicographers and commentators also explain qisṭās through justice.
Balance and justice should nevertheless remain distinct.
The balance is the measuring instrument; justice is the desired quality of measurement and human conduct.
An instrument can help realize justice without replacing personal honesty and responsibility.
In both Qur’anic occurrences, wa-zinū shows the tangible weighing-instrument sense retaining a central role.
Quranic Arabic Corpus: two nominal occurrences of qisṭās
The broader justice-related use can therefore be recognized without removing the instrument from the verse translations.
4. Qur’anic Use in Al-Isrāʾ 17:35
Al-Isrāʾ 17:35
وَأَوْفُوا الْكَيْلَ إِذَا كِلْتُمْ وَزِنُوا بِالْقِسْطَاسِ الْمُسْتَقِيمِ ذَٰلِكَ خَيْرٌ وَأَحْسَنُ تَأْوِيلًا
wa-awfū al-kayla idhā kiltum wa-zinū bi-l-qisṭāsi al-mustaqīmi dhālika khayrun wa-aḥsanu taʾwīlan
Forqan’s existing Persian translation, rendered here in English:
“And when you measure, give full measure, and weigh with an accurate balance; that is better and finer in outcome.”
The verse places two actions together: measuring by capacity and weighing.
Awfū al-kayla idhā kiltum concerns giving full measure.
Wa-zinū bi-l-qisṭāsi al-mustaqīmi commands weighing with an accurate balance.
The actions are related in trading, but differ.
Measuring by Capacity and by Weight
Capacity measurement generally determines an amount through capacity or volume.
Grain or liquid, for example, may be measured with a vessel of known capacity.
Weighing instead determines an amount by weight.
The balance here is the instrument establishing actual weight.
Kayl and wazn are consequently two measurement methods, usable for different commodities or even the same commodity in different circumstances.
The Qur’an mentions each separately.
That distinction matters: an accurate capacity measure does not guarantee an accurate balance, or vice versa.
A seller might give short measure through an incorrect measuring vessel, or tamper with a balance to provide less than the buyer is due.
Both cases concern depriving the trading partner of their right.
The Structure of Bi-l-Qisṭāsi
Bi-l-qisṭāsi consists of the preposition bi-, the definite article al-, and the noun qisṭās.
Bi- here introduces the instrument or means of the action.
Zinū means “weigh”; bi-l-qisṭāsi identifies the instrument used to do so.
The construction supports the balance meaning.
Translating qisṭās solely as “justice” would produce “weigh with justice.”
That conveys an intelligible ethical purpose, but obscures the measuring instrument named in the expression.
“With the balance” is therefore more direct, with al-mustaqīm specifying its desired quality.
Al-Mustaqīm: Accuracy and Freedom from Deviation
Al-mustaqīm belongs to Q W M and the istifʿāl form.
Arabic istiqāmah concerns straightness, soundness, and absence of deviation.
In al-qisṭāsi al-mustaqīmi, the adjective qualifies the balance.
Straightness here should not be restricted to a balance part’s outward shape.
An instrument might appear straight and sound while producing an incorrect weight.
Conversely, differently constructed balances can still operate accurately.
Contextually, al-mustaqīm concerns accurate weighing, due measure, and freedom from distortion in the result.
This can involve a sound instrument, proper adjustment, and honest use.
The verse itself specifies no technical procedure for adjusting or testing a balance.
The phrase therefore does not mandate a particular balance type, number of pans, or instrument construction.
The explicit command is to weigh with an accurate instrument.
Dhālika Khayrun wa-Aḥsanu Taʾwīlan
The verse ends by describing that conduct as better and finer in outcome.
Dhālika points back to the preceding instructions about giving full measure and weighing accurately.
The verse consequently goes beyond describing a measurement method to assess its value and consequences.
Accurate measurement preserves people’s rights and prevents loss of property and trading disputes.
It can promote trust and sound economic relationships.
These should be recognized as understandable consequences of obeying the command, rather than components of qisṭās’s lexical meaning.
Qisṭās itself means neither social trust nor a good outcome; those concepts arise from the conduct and result described by the verse as a whole.
Al-Ṭabarī: accurate weighing and the finer outcome
Connection with Adjacent Verses
Al-Isrāʾ 17:34 commands preserving the orphan’s rights and fulfilling commitments.
Al-Isrāʾ 17:35 then turns to measures and balances.
Al-Isrāʾ 17:36 forbids pursuing what one has no knowledge of.
Accurate weighing thus stands among instructions concerning rights, trustworthiness, and human responsibility.
In this context, balance accuracy is more than a technical matter separate from ethics: its result directly affects the trading partner’s right.
The ethical connection nevertheless does not change the word’s direct meaning.
Qisṭās remains the balance; al-mustaqīm describes its accuracy in weighing.
5. Qur’anic Use in Al-Shuʿarāʾ 26:182
Al-Shuʿarāʾ 26:182
وَزِنُوا بِالْقِسْطَاسِ الْمُسْتَقِيمِ
wa-zinū bi-l-qisṭāsi al-mustaqīmi
Forqan’s existing Persian translation, rendered here in English:
“And weigh with an accurate balance.”
The same expression as in Al-Isrāʾ 17:35 recurs here.
Structurally, bi-l-qisṭāsi introduces the weighing instrument, and al-mustaqīmi describes it.
Its context differs from the Al-Isrāʾ verse, however.
Shuʿayb’s Instruction about Trading
Al-Shuʿarāʾ 26:176 describes the People of the Thicket denying the messengers. In Al-Shuʿarāʾ 26:177 Shuʿayb calls them to mindfulness, and in Al-Shuʿarāʾ 26:179 to mindfulness and obedience.
Al-Shuʿarāʾ 26:181 commands giving full measure and avoiding short measure.
Al-Shuʿarāʾ 26:182 then commands weighing with an accurate qisṭās.
Al-Shuʿarāʾ 26:183 forbids diminishing people’s things and spreading corruption on earth.
The three verses have a clear connection.
The first command concerns full measure.
The second concerns accuracy in the balance and weighing.
The third widens the issue: people’s rights and things should not be diminished, nor corruption spread on earth.
Observing qisṭās therefore cannot be treated as merely technical and unrelated to other people’s rights.
The balance determines quantity, but misuse can deprive people of what they are due.
Why Does Qisṭās Accompany Al-Mustaqīm?
Both Qur’anic occurrences have al-mustaqīm.
The pairing emphasizes accuracy in both the instrument and measurement.
An instrument determining quantity must yield a trustworthy result.
A balance distorting the result cannot correctly establish what the trading parties are due.
Accuracy nevertheless requires more than possessing a sound device.
Someone can intentionally understate a quantity using a sound instrument, or lie when recording its result.
Obeying the Qur’anic command therefore requires proper, honest use alongside a reliable instrument.
This follows from the command’s connection with fairness in trade; qisṭās itself does not contain every aspect of the seller’s ethical conduct in its lexical meaning.
Is Qisṭās Restricted to Old Balances?
Earlier weighing instruments were generally mechanical.
The command is nevertheless not restricted to one instrument construction.
Goods today may be weighed on mechanical or electronic scales.
Functionally, any device accurately determining weight against a trustworthy standard can be a weighing instrument.
The principle therefore survives changes in weighing technology.
This does not establish that the Qur’anic word specifically predicted electronic scales or modern scientific methods.
The word had an established meaning in the Arabic of revelation’s period; new examples can be compared with it by function.
That applies a familiar concept to new instruments, rather than discovering a hidden scientific meaning in the word.
Qisṭās and Economic Corruption
The Al-Shuʿarāʾ passage places short measure and weight alongside corruption on earth.
Measurement fraud consequently concerns more than a minor disagreement between seller and buyer.
If dishonest capacity and weight measurement become widespread, people’s rights suffer broadly and mutual trust declines.
An accurate qisṭās can thus contribute to sound economic relationships.
These social consequences should not transform the lexical meaning of qisṭās into “a just economic system.”
The verse names a particular weighing instrument; together with the other instructions, it illustrates the wider principle of respecting people’s rights.
7. Conclusions and Translation Proposals
Arabic qisṭās names a balance or weighing instrument, lexically associated with accuracy and justice in measurement.
Early sources record both qisṭās and qusṭās, with plural qasāṭīs.
Views of its historical origin differ. Some connect it with Arabic Q S Ṭ; others, including early lexicographers, identify it as an Arabized loanword.
Comparative studies examine Greek and Aramaic weighing and measuring forms too, without a settled agreement on its precise source or transmission route.
The disagreement should not lead to invented etymologies or obscure the word’s clear Qur’anic meaning.
The family occurs twice in the Qur’an, in the identical form bi-l-qisṭāsi.
Al-Isrāʾ 17:35 places weighing with an accurate qisṭās alongside full capacity measurement, ending with the conduct’s superiority and finer outcome.
Al-Shuʿarāʾ 26:182 repeats the command in Shuʿayb’s speech, alongside full measure and the prohibition of diminishing people’s rights.
Both uses directly mean the balance.
Al-mustaqīm emphasizes accurate measurement free of distortion.
Qisṭās should therefore not be translated solely as abstract justice, omitting the weighing instrument.
Nor should it be restricted to large balances, the qabbān, or one particular construction of early instrument.
Brief root meaning: A balance or weighing instrument; lexically, especially an accurate, trustworthy balance used to maintain fairness in weighing.
Qur’anic forms and proposed translations:
Bi-l-qisṭāsi — Al-Isrāʾ 17:35: with the balance; with al-mustaqīm, a balance showing weight accurately and without distortion. Proposed translation of the full phrase: “with an accurate balance.”
Bi-l-qisṭāsi — Al-Shuʿarāʾ 26:182: with the balance; the proper weighing instrument in Shuʿayb’s trading instruction. Proposed translation of the full phrase: “with an accurate balance.”
Forqan’s existing Persian translation preserves the word’s principal meaning and accompanying adjective well in both occurrences.
Al-Isrāʾ 17:35, Forqan’s Persian translation rendered in English:
“And when you measure, give full measure, and weigh with an accurate balance; that is better and finer in outcome.”
Al-Shuʿarāʾ 26:182, Forqan’s Persian translation rendered in English:
“And weigh with an accurate balance.”
The principal finding is that Qur’anic qisṭās names the weighing instrument, while al-mustaqīm and the context of respecting people’s rights make accuracy and fairness in measurement central concerns.
A balance can determine quantity, but its fair use depends on a reliable instrument and honest human conduct.
The lexical instrument meaning should therefore remain distinct from the ethical principle of justice, while preserving their actual connection in the verses.
Measures and balances in the Qur’an are more than trading implements: their use can demonstrate honoring other people’s rights or become a means of violating them.
This follows from the combined commands and contexts, while qisṭās itself continues to mean “balance.”