The Qur’anic root TH ʿ B

1. Semantic core and root forms

In Maqāyīs al-Lughah, Ibn Fāris explains the root’s semantic core as follows:

«الثَّاءُ وَالْعَيْنُ وَالْبَاءُ أَصْلٌ يَدُلُّ عَلَى امْتِدَادِ الشَّيْءِ وَانْبِسَاطِهِ»

al-thāʾu wa-al-ʿaynu wa-al-bāʾu aṣlun yadullu ʿalā imtidādi al-shayʾi wa-inbisāṭihi

The letters thāʾ, ʿayn, and bāʾ indicate the extension and spreading out of something.

He explains that this meaning may apply to water or other things, giving as an example water flowing after its passage has been opened.

Maqāyīs al-Lughah: extension and spreading out

Kitāb al-ʿAyn also records the verb thaʿaba in connection with water:

«ثَعَبْتُ الْمَاءَ أَثْعَبُهُ ثَعْبًا»

thaʿabtu al-māʾa athʿabuhu thaʿban

This expression is used when someone opens an outlet for water and sets it flowing.

Inthaʿaba is used of water or blood itself: the liquid flows or pours out from somewhere.

The difference between thaʿaba and inthaʿaba shows that one construction foregrounds an agent setting something flowing, while the other foregrounds the liquid’s own flow.

Kitāb al-ʿAyn: setting water flowing and the flow of blood

Thaʿb: a watercourse or torrent channel

In Arabic, thaʿb denotes a watercourse or a channel carrying water in a valley. Thuʿbān is also recorded as its plural.

This usage belongs to environments where rainfall collects along particular routes and runs through higher and lower ground.

In such an environment, the water itself, its course, and its outlet are distinct.

Thaʿb can denote the course, whereas mathʿab denotes a channel or outlet, such as a water spout carrying rainwater off a roof or out of a basin.

Tahdhīb al-Lughah transmits from Abū ʿAmr that thaʿb is a valley’s watercourse. It also transmits from Al-Farrāʾ a grouping of the word with places where water collects.

Al-Layth gives another explanation of thaʿb: debris collecting in a torrent channel. Al-Azharī finds this explanation inadequate and maintains that thaʿb is the course itself, rather than the debris collecting in it.

This disagreement shows that even the root’s material uses require distinctions between lexicographers’ definitions.

Lisān al-ʿArab: Al-Azharī’s criticism of Al-Layth’s definition

Thuʿbān: a name for a serpent

Thuʿbān follows the pattern fuʿlān. Its plural in the animal sense is thaʿābīn.

Many early sources use this name for a large, long serpent. Al-Khalīl ibn Aḥmad, Ibn Fāris, and other lexicographers emphasize its size and bodily length.

Nevertheless, not all lexicographers restrict the word to a large serpent.

Ibn Shumayl is reported to apply thuʿbān to all snakes, small and large, male and female. Abū Khayrah, by contrast, calls it a male snake, while Quṭrub offers a narrower description involving a large snake with a particular coloration.

Early Arabic authorities thus differ over the scope of thuʿbān. Large size and an elongated body are prominent in many definitions, but one cannot state categorically that every Arabic occurrence denotes only a male snake or only one of a specified size and color.

Lisān al-ʿArab: differing definitions from Ibn Shumayl, Abū Khayrah, and Quṭrub

This difference matters for Qur’anic translation. “Large serpent,” or the Persian azhdahā understood in that sense, may convey the feature emphasized by some early definitions. The word alone does not require a particular sex, color, or exact size.

2. The connection between flowing water and a serpent’s movement

At first sight, flowing water and a serpent are clearly different: one is a liquid, the other an animal. Yet extension and movement can explain a semantic connection within this root family.

Water issuing from an opening moves along a course. Its flow may be straight or winding, and the terrain determines its route.

A serpent likewise has an elongated body and advances along the ground. Its winding motion can resemble water flowing through a curving channel.

Ibn Fāris explains thuʿbān through this same principle. After identifying extension and spreading out, he connects the name for the large, long serpent with its bodily extension and movement.

This semantic explanation is intelligible, but its limits must be respected.

First, thuʿbān was an established Arabic name for a serpent. Hearing it did not necessarily require an Arabic speaker to reconstruct an image of flowing water each time.

Second, Ibn Fāris’s account of a semantic connection does not itself establish the historical origin of the animal’s name. It may explain the proximity of the meanings, but deciding which usage came first, or exactly how the name arose, requires independent historical evidence.

Third, thuʿbān in the Qur’an should not be treated as simultaneously meaning both a serpent and flowing water. A shared root does not transfer every meaning in the lexical family to each derivative.

With this distinction, flow and extension can illuminate the root family without displacing the Qur’anic noun’s clear meaning.

3. Early Arabic usage

Early Arabic uses of TH ʿ B are not confined to the Qur’an.

Thaʿaba al-māʾa is recorded for causing water to flow, and inthaʿaba al-damu for blood flowing. These examples show that the moving substance can be water, blood, or another liquid.

In watercourse terminology, thaʿb denotes a torrent’s course and mathʿab a channel through which water exits.

These meanings concern everyday life and knowledge of waterways, showing that the root’s Arabic scope extends beyond the animal’s name.

A poetic witness from Ḥumayd ibn Thawr

Tahdhīb al-Lughah and Lisān al-ʿArab transmit a verse by Ḥumayd ibn Thawr that uses thuʿbān in a simile:

فَلَمَّا أَتَتْهُ أَنْشَبَتْ فِي خِشَاشِهِ
زِمَامًا كَثُعْبَانِ الْحَمَاطَةِ مُحْكَمَا

fa-lammā atat-hu anshabat fī khishāshihi / zimāman ka-thuʿbāni al-ḥamāṭati muḥkamā

Translation:

“When she reached him, she fastened a rein to his wooden nose-peg, firmly secured like the serpent of the ḥamāṭah.”

The poet compares an animal’s rein to a thuʿbān. The rein’s elongated, winding shape may be the point of comparison with a serpent’s body. Khishāsh here is a wooden peg placed in a camel’s nose; translating it simply as a “ring” would obscure that detail.

Jamharat al-Lughah: khishāsh, a camel’s wooden nose-peg

The verse shows that thuʿbān was an established poetic name for a serpent and could describe the shape of other objects through comparison.

Ḥamāṭah in this expression refers to vegetation or a place associated with it. The verse alone, however, does not establish the animal’s species, size, color, or degree of venomousness.

Ḥumayd ibn Thawr was a mukhadram poet, one who lived across the pre-Islamic and Islamic periods. Unless the date of this verse is established, it should not be presented as certainly predating Qur’anic revelation.

Lisān al-ʿArab: the Ḥumayd ibn Thawr witness

A witness recorded in Kitāb al-ʿAyn

Kitāb al-ʿAyn also includes a poetic fragment when explaining thuʿbān:

«عَلَى نَهْجٍ كَثُعْبَانِ الْعَرِينِ»

ʿalā nahjin ka-thuʿbāni al-ʿarīni

On a surface reading: “Upon a path like the serpent of the ʿarīn.” This renders a short fragment, rather than definitively reconstructing the meaning of the full verse.

Here thuʿbān appears in a comparison introduced by ka-, “like.” This short fragment alone does not establish the complete subject of comparison or the poet’s precise intention.

The cited passage identifies neither the poet nor the complete verse. It is useful evidence of recorded usage, but it cannot confidently be attributed to a particular poet or assigned a date.

Al-ʿAyn: short witness and editors’ note on its unidentified poet

Other members of the root family

Lexicons also record uthʿūb for an outflow of water or blood, and uthʿubān as a description of a large, impressive face.

Thuʿbah is also recorded as the name of another animal, grouped with gecko-like creatures in some sources. The vocalization thuʿabah is recorded too; Lisān al-ʿArab reports the variation between a quiescent ʿayn and one bearing fatḥah.

These usages remind us that similar word forms do not necessarily identify the same referent. Thuʿbah in that use is not the Qur’anic thuʿbān, and describing a face as uthʿubān does not mean that the person is a serpent.

Lisān al-ʿArab: uthʿubān and variant vocalizations of thuʿbah

Each derivative must be understood through its actual form, context, and usage.

4. Qur’anic occurrences of TH ʿ B

Al-Aʿrāf 7:107

Al-Aʿrāf 7:107

فَأَلْقَىٰ عَصَاهُ فَإِذَا هِيَ ثُعْبَانٌ مُّبِينٌ

fa-alqā ʿaṣāhu fa-idhā hiya thuʿbānun mubīnun

English rendering of Forqan’s current Persian wording (marked provisional on the verse page):

“Then he cast down his staff, and suddenly it was a manifest great serpent.”

Moses casts down his staff before Pharaoh, and what had been a staff appears as thuʿbānun mubīnun, a manifest serpent.

Fa-idhā expresses the suddenness of the event. The pronoun hiya refers back to the staff, and thuʿbānun identifies what has suddenly appeared.

Mubīnun qualifies thuʿbānun. It belongs to another root and here indicates the clear, manifest character of what has appeared.

Lexical usage supports understanding thuʿbān as a serpent, one characterized in many early definitions by its large size and long body.

The word itself, however, specifies neither its exact size nor its color or species.

Some exegetical reports describe an extraordinarily large snake, particular colors, or remarkable behavior. Those details are absent from the verse and should not be imported into translation as part of the root’s meaning.

In the same context, Al-Aʿrāf 7:106 shows Pharaoh asking Moses to produce a sign if he has brought one. Verse 107 answers that request.

This connection shows that the serpent’s appearance functions in the narrative as a sign for those present, rather than as an unrelated description of an ordinary animal.

The meaning of a sign or proof comes from the narrative context, however, not from the lexical meaning of thuʿbān.

Al-Shuʿarāʾ 26:32

Al-Shuʿarāʾ 26:32

فَأَلْقَىٰ عَصَاهُ فَإِذَا هِيَ ثُعْبَانٌ مُّبِينٌ

fa-alqā ʿaṣāhu fa-idhā hiya thuʿbānun mubīnun

English rendering of Forqan’s current Persian wording (marked provisional on the verse page):

“Then he cast down his staff, and suddenly it became a manifest great serpent.”

The Arabic text is identical to Al-Aʿrāf 7:107. The two occurrences thus do not differ in word form, sentence construction, or the qualification mubīn.

In Al-Shuʿarāʾ, too, the event belongs to Moses’ dialogue with Pharaoh.

Moses has been commissioned by the Lord and speaks of his message before Pharaoh. When Moses mentions bringing a sign, Pharaoh asks him to produce it.

After the staff is cast down and the serpent appears, another sign is described in Al-Shuʿarāʾ 26:33.

The serpent’s narrative role is clear in both surahs: the staff becomes a manifest serpent in the presentation of a sign.

This similarity should not lead a root study to omit one occurrence or count them as one. They are two separate textual occurrences, although they relate the same event in identical language.

Does thuʿbān also mean a stream of water in the Qur’an?

Besides naming a serpent, Arabic records thuʿbān as a plural of thaʿb in the sense of watercourses.

The existence of that lexical use does not, by itself, make the word ambiguous in the Moses passages.

Elsewhere the Qur’an describes the same staff as a ḥayyah and compares its movement to that of a jānn. These related passages show that thuʿbān in the two verses under discussion denotes a serpent.

Translating it as a “stream of water,” “torrent,” or “water channel” is therefore inconsistent with the narrative context and the related verses.

The image of flowing and extending water may illuminate the root’s lexical connections, but it does not replace the Qur’anic noun’s specific meaning.

5. Thuʿbān, ḥayyah, and jānn in the Moses narrative

The Qur’an does not use thuʿbān alone when describing Moses’ staff after it is cast down. Other passages also use ḥayyah and jānn.

Their differences help establish the precise place of thuʿbān.

TH ʿ B (thuʿbān) and Ḥ Y Y (ḥayyah): a more specific name and the general word for a snake

Study of Ḥ Y Y

Ṭā Hā 20:20

فَأَلْقَاهَا فَإِذَا هِيَ حَيَّةٌ تَسْعَىٰ

fa-alqāhā fa-idhā hiya ḥayyatun tasʿā

Translation:

“Then he cast it down, and suddenly it was a snake moving swiftly.”

Ḥayyah is the general Arabic word for a snake. It does not itself determine a particular size, color, or sex.

Thuʿbān is also a serpent’s name, but many early uses and definitions apply it especially to a large, long serpent.

The two expressions need not conflict. An animal may be a ḥayyah and also be called a thuʿbān.

In Ṭā Hā, the verb tasʿā makes the snake’s movement explicit. In Al-Aʿrāf and Al-Shuʿarāʾ, mubīn emphasizes the manifest character of what appears.

Each verse thus describes the matter from a particular angle.

The different words do not establish that two different animals necessarily appeared. Nor should one assert without evidence that the staff first became a small snake and subsequently increased in size. The expressions themselves do not establish that sequence.

TH ʿ B (thuʿbān) and J N N (jānn): the animal’s appearance and manner of movement

Study of J N N

Al-Naml 27:10

وَأَلْقِ عَصَاكَ ۚ فَلَمَّا رَآهَا تَهْتَزُّ كَأَنَّهَا جَانٌّ وَلَّىٰ مُدْبِرًا وَلَمْ يُعَقِّبْ ۚ يَا مُوسَىٰ لَا تَخَفْ إِنِّي لَا يَخَافُ لَدَيَّ الْمُرْسَلُونَ

wa-alqi ʿaṣāka fa-lammā raʾāhā tahtazzu ka-annahā jānnun wallā mudbiran wa-lam yuʿaqqib yā Mūsā lā takhaf innī lā yakhāfu ladayya al-mursalūna

Translation:

“And cast down your staff. When he saw it moving as though it were a snake, he turned away and did not return. O Moses, do not fear; the messengers do not fear in My presence.”

This verse contains an important syntactic distinction.

It does not say fa-idhā hiya jānnun, “and suddenly it was a jānn”; it says tahtazzu ka-annahā jānnun, “moving as though it were a jānn.”

The statement concerns the staff’s movement and its comparison to a jānn.

Lexicons explain jānn in this use as a kind of snake, often a small, lightly moving one.

The verse can thus be understood as describing movement like that of a light, quick-moving snake.

This construction need not conflict with thuʿbān in the other two surahs: one names the animal, while the other describes its movement through a simile.

Al-Qaṣaṣ 28:31 likewise uses ka-annahā jānnun in connection with the staff’s movement.

Nevertheless, the text’s explicit statements must be distinguished from explanations proposed to reconcile the passages.

A large serpent in size with the movement of a small, quick snake is a possible explanation consistent with the constructions. The Qur’an, however, does not specify an exact size or stages of physical transformation.

Lisān al-ʿArab: Al-Zajjāj’s explanation of thuʿbān and jānn

Jānn here also shares its form with al-jānn in passages about the creation of jinn. That shared form does not establish that Moses’ staff became a being of the jinn.

The context, the verb tahtazzu, and the comparison introduced by ka-annahā indicate snake-like movement.

Does thuʿbān name a particular snake species?

Early Arabic uses different names for snakes. Some concern size, others color, behavior, or habitat.

These names should not be equated with modern zoological classifications without historical investigation.

Early sources sometimes use thuʿbān broadly for a snake and sometimes more narrowly for a large or male one. This variation precludes identifying one biological species as its certain Qur’anic referent.

For example, neither the word nor the related verses establish that Moses’ thuʿbān was necessarily a cobra, viper, python, or another particular snake.

Reported colors or extraordinary features in narrative traditions do not replace Qur’anic evidence either.

Translation and root study can securely identify a serpent and recognize that large size and bodily length may be prominent in the word’s usage.

6. Translation proposals for Forqan

For water and other liquids, thaʿaba can be translated, according to the construction, as “set flowing,” “open an outlet for water,” or “cause to flow.”

Inthaʿaba, applied to water or blood, means “flow,” “pour out,” or “begin to flow.”

For geographical thaʿb, “watercourse,” “torrent channel,” or “channel carrying water” is suitable. Mathʿab can mean a “water spout” or “outlet channel.”

For Qur’anic thuʿbān, however, the equivalent must preserve the animal’s name.

“Snake” is a clear general equivalent. “Large serpent” expresses the feature prominent in many early definitions. The Persian azhdahā can likewise convey a very large, fearsome serpent.

In contemporary Persian, however, azhdahā can also suggest a mythical dragon with features such as wings or fire-breathing. Those features are absent from thuʿbān itself.

If azhdahā is retained in Persian, it should therefore be understood as a large serpent, without additional mythical features.

Qur’anic form: thuʿbānun

Brief root meaning: Extension and continuous movement; in material uses, the flow of water and other liquids.

Meaning in this verse: A serpent; in a prominent early usage, especially a large, long one.

The form has the same meaning in Al-Aʿrāf 7:107 and Al-Shuʿarāʾ 26:32.

An English rendering of Forqan’s current Persian wording for Al-Aʿrāf 7:107 is:

“Then he cast down his staff, and suddenly it was a manifest great serpent.”

That wording is consistent with an established use of thuʿbān, provided Persian azhdahā is understood as a large serpent.

For direct lexical clarity, “large serpent” is also a straightforward and less ambiguous option. This translational difference alone, however, does not justify changing Forqan’s installed verse wording.

7. Conclusion

The Arabic root TH ʿ B is associated with extension, movement, and flow. Water, blood, torrent channels, and water outlets illustrate its semantic field.

Thuʿbān is also a name for a serpent. Many early sources emphasize its large size and long body, although some lexicographers apply it to all snakes.

The root occurs in only two Qur’anic verses, each time as thuʿbānun. Both present Moses’ staff, after he casts it down, as a manifest serpent.

Comparison with Ṭā Hā 20:20, Al-Naml 27:10, and Al-Qaṣaṣ 28:31 shows thuʿbān, ḥayyah, and jānn describing the same subject matter through different constructions and roles. Ḥayyah is the general word for a snake; thuʿbān in a prominent early usage particularly suggests a large, long serpent; and jānn in the passages discussed occurs in a simile describing the staff’s movement.

These differences do not establish an exact size, sex, color, species, or sequence of transformation.

Nor does a possible connection between the serpent’s name and flow or extension turn the Qur’anic thuʿbān into water or a torrent.

In Qur’anic translation, “snake,” or “large serpent” when retaining a prominent feature of early usage, is therefore defensible. Persian azhdahā can also be used in the sense of a large serpent, but should not introduce additional mythical attributes.