The Qur’anic Root K S B

1. The Semantic Core in Early Arabic

In the early language, كَسَبَ (kasaba) was connected with seeking, pursuing something, and acquiring it. Wealth and provision were among the clearest instances of this usage, but the word itself was not restricted to wealth.

Ibn Faris records the field of seeking and attaining for this root. Al-Raghib al-Isfahani likewise understands kasb as something a person pursues to obtain a benefit or gain, although what someone pursues in the belief that it is beneficial may ultimately harm them.

Pre-Islamic poetry also recognizes this range. Al-Aʿsha speaks of:

الْكَسْبَ الْخَبِيثَ

Al-kasba al-khabītha.

meaning “impure acquisition.” The adjective الخبيث (al-khabīth) itself specifies the kind of acquisition. This construction shows that kasb is neither good nor bad in itself.

Poetry attributed to Umayyah ibn Abi al-Salt also uses اكتسب المال (iktasaba al-māl) for acquiring wealth. Thus Form VIII, too, was not restricted to sin or something negative in the early language.

The root’s defensible core is:

Seeking and obtaining something that becomes attributable to the agent.

2. The Qur’an Extends Kasb from Wealth to Action

Al-Baqarah states:

بَلَىٰ مَن كَسَبَ سَيِّئَةً وَأَحَاطَتْ بِهِ خَطِيئَتُهُ

Balā man kasaba sayyiʾatan wa-aḥāṭat bihi khaṭīʾatuhu.

Indeed, whoever acquires an evil deed and is encompassed by their wrongdoing...

Al-Baqarah 2:81

Here what has been acquired is not wealth; it is a sayyiʾah, an evil deed.

Other ayahs repeatedly use constructions such as مَا كَسَبُوا، مَا كَسَبَت، بِمَا كَانُوا يَكْسِبُونَ (mā kasabū, mā kasabat, bi-mā kānū yaksibūn). Human action is not simply an event that happens and ends; it obtains something for the person and returns to their own account.

This point is particularly clear in Al-Baqarah:

تِلْكَ أُمَّةٌ قَدْ خَلَتْ لَهَا مَا كَسَبَتْ وَلَكُم مَّا كَسَبْتُمْ

Tilka ummatun qad khalat lahā mā kasabat wa-lakum mā kasabtum.

That was a community that has passed away; theirs is what they acquired, and yours is what you acquired.

Al-Baqarah 2:134

The same expression is repeated in ayah 141.

Earlier generations have what they themselves acquired, and the next generation likewise faces its own acquisition. Ethnic or historical affiliation does not take the place of personal action.

In Al-Muddaththir, this relationship is expressed even more concisely:

كُلُّ نَفْسٍ بِمَا كَسَبَتْ رَهِينَةٌ

Kullu nafsin bi-mā kasabat rahīnatun.

Every soul is held in pledge for what it has acquired.

Al-Muddaththir 74:38

A difference in tendency between ʿamal, action, and kasb, acquisition, can therefore be expressed as follows:

ʿAmal is the doing of the action itself; kasb is what the agent obtains through that action and what becomes attributable to them.

This difference is not absolute, but it clarifies the two words’ perspectives.

3. Hearts and Hands Also “Acquire”

The Qur’an does not attribute kasb only to the person as a whole. Sometimes the heart or hands appear in the sentence construction.

Concerning oaths, it says:

لَّا يُؤَاخِذُكُمُ اللَّهُ بِاللَّغْوِ فِي أَيْمَانِكُمْ وَلَٰكِن يُؤَاخِذُكُم بِمَا كَسَبَتْ قُلُوبُكُمْ

Lā yuʾākhidhukumu Allāhu bi-l-laghwi fī aymānikum wa-lākin yuʾākhidhukum bi-mā kasabat qulūbukum.

The God does not hold you accountable for idle speech in your oaths, but holds you accountable for what your hearts have acquired.

Al-Baqarah 2:225

Here kasb is not only outward conduct. What has taken shape in the heart and become attributable to a person can also be subject to accountability.

Other ayahs contain the expression:

بِمَا كَسَبَتْ أَيْدِيكُمْ

Bi-mā kasabat aydīkum.

or forms close to it.

Attributing acquisition to the hands does not mean that only physical hand movements are intended. In this construction, the hand represents what the person has done themselves.

Through a single root, the Qur’an thus encompasses both the inward sphere and outward action.

4. Kasb and the Consequences of Action

One important feature of the Qur’anic use of K S B is its recurring connection with consequences.

Ash-Shura states:

وَمَا أَصَابَكُم مِّن مُّصِيبَةٍ فَبِمَا كَسَبَتْ أَيْدِيكُمْ

Wa-mā aṣābakum min muṣībatin fa-bi-mā kasabat aydīkum.

Whatever calamity befalls you is because of what your hands have acquired.

Ash-Shura 42:30

And in Ar-Rum:

ظَهَرَ الْفَسَادُ فِي الْبَرِّ وَالْبَحْرِ بِمَا كَسَبَتْ أَيْدِي النَّاسِ

Ẓahara al-fasādu fī al-barri wa-l-baḥri bi-mā kasabat aydī al-nāsi.

Corruption has appeared on land and sea because of what people’s hands have acquired.

Ar-Rum 30:41

In both ayahs, human action has consequences. What a person has acquired returns as an outcome to the world or to themselves.

This connection is also clear in the ayahs of reckoning:

وَوُفِّيَتْ كُلُّ نَفْسٍ مَّا كَسَبَتْ

Wa-wuffiyat kullu nafsin mā kasabat.

Every soul is given in full what it has acquired.

Al-Imran 3:25

And:

وَلِتُجْزَىٰ كُلُّ نَفْسٍ بِمَا كَسَبَتْ

Wa-li-tujzā kullu nafsin bi-mā kasabat.

So that every soul may be recompensed for what it has acquired.

Al-Jathiyah 45:22

Nevertheless, the ayah in Ash-Shura should not be turned into an unlimited rule declaring every individual illness, accident, or calamity a direct consequence of that person’s sin. The Qur’an also discusses other experiences, such as trial and testing. The root K S B does not itself produce such a theory.

5. Kasb within the Qur’an’s Language of Gain and Loss

Alongside “kasb,” the Qur’an repeatedly uses the language of trade to express choice and outcome.

In Al-Baqarah, it says of those who exchanged guidance for misguidance:

أُولَٰئِكَ الَّذِينَ اشْتَرَوُا الضَّلَالَةَ بِالْهُدَىٰ فَمَا رَبِحَت تِّجَارَتُهُمْ

Ulāʾika alladhīna ishtaraw al-ḍalālata bi-l-hudā fa-mā rabiḥat tijāratuhum.

Those are the ones who bought misguidance at the price of guidance, so their trade brought no profit.

Al-Baqarah 2:16

Elsewhere it speaks of تِجَارَةً لَّن تَبُورَ (tijāratan lan tabūr), a trade that will not perish.

Words for buying, trade, profit, and loss are sometimes used in the Qur’an for matters that are not directly economic. Human choice is pictured as a transaction in which one gives something and receives something, ending in gain or loss.

Kasb can also be understood within this network, because what a person does obtains something for them.

But this metaphorical network should not be equated with the root’s definition. K S B existed in Arabic independently of this metaphor, and the Qur’an uses it alongside other words concerning attainment and outcome.

6. Kasb Can Be Good or Evil

The root itself has no fixed moral value.

Al-Baqarah states:

أُولَٰئِكَ لَهُمْ نَصِيبٌ مِّمَّا كَسَبُوا

Ulāʾika lahum naṣībun mimmā kasabū.

They have a share of what they have acquired.

Al-Baqarah 2:202

In this ayah’s context, kasb accompanies a desirable outcome.

By contrast:

بَلَىٰ مَن كَسَبَ سَيِّئَةً

Balā man kasaba sayyiʾatan.

Indeed, whoever acquires an evil deed...

Al-Baqarah 2:81

And:

وَبَدَا لَهُمْ سَيِّئَاتُ مَا كَسَبُوا

Wa-badā lahum sayyiʾātu mā kasabū.

The evils of what they had acquired became apparent to them.

Az-Zumar 39:48

In these cases, the negative direction comes from sayyiʾah, evil, and the ayah’s context.

The same root can be used for good and evil, because “kasb” expresses acquisition and obtaining itself, rather than the value of what has been obtained.

7. كَسَبَ (Kasaba) and اكْتَسَبَ (Iktasaba)

The Qur’an uses كَسَبَ (kasaba) 62 times and اكْتَسَبَ (iktasaba) five times.

The best-known contrast occurs at the end of Al-Baqarah:

لَهَا مَا كَسَبَتْ وَعَلَيْهَا مَا اكْتَسَبَتْ

Lahā mā kasabat wa-ʿalayhā mā iktasabat.

For it is what it has acquired, and against it is what it has acquired for itself.

Al-Baqarah 2:286

Because كَسَبَتْ (kasabat) accompanies لَهَا (lahā), and اكْتَسَبَتْ (iktasabat) accompanies عَلَيْهَا (ʿalayhā), it has sometimes been said that kasb belongs specifically to good and iktisāb specifically to evil.

Other Qur’anic usages, however, reject this boundary.

An-Nisa states:

لِّلرِّجَالِ نَصِيبٌ مِّمَّا اكْتَسَبُوا وَلِلنِّسَاءِ نَصِيبٌ مِّمَّا اكْتَسَبْنَ

Li-l-rijāli naṣībun mimmā iktasabū wa-li-l-nisāʾi naṣībun mimmā iktasabna.

For men is a share of what they have acquired, and for women is a share of what they have acquired.

An-Nisa 4:32

Here اكْتَسَبُوا (iktasabū) and اكْتَسَبْنَ (iktasabna) have no negative meaning in themselves.

We also read in An-Nur:

لِكُلِّ امْرِئٍ مِّنْهُم مَّا اكْتَسَبَ مِنَ الْإِثْمِ

Li-kulli imriʾin minhum mā iktasaba mina al-ithmi.

For each of them is the amount of sin they have acquired for themselves.

An-Nur 24:11

The negative sense comes from مِنَ الْإِثْمِ (mina al-ithm), “of sin.”

A Defensible Difference: Kasb Is Broader, Iktisāb More Personal

Al-Raghib al-Isfahani proposes another difference that is more compatible with the linguistic evidence.

In his view, kasb can describe what someone obtains for themselves or for another. In Arabic, for example, a person can be called the “earner for their household,” meaning that they obtain something for their family.

Iktisāb, however, more particularly describes what a person obtains for themselves.

In this respect:

Every iktisāb is kasb, but not every kasb is iktisāb.

This difference helps explain some ayahs, but should still not be turned into a rigid rule. Each ayah’s context takes precedence.

In Al-Baqarah 2:286, alongside the distinction between لها / عليها (lahā / ʿalayhā), the choice of اكتسبت (iktasabat) can emphasize what the person has obtained for themselves and for which responsibility returns directly to them. But the good and evil character of the two parts is understood primarily from lahā / ʿalayhā, “for it / against it,” rather than from the morphological form alone.

Some grammarians have also seen a degree of greater exertion and effort in اكتسب (iktasaba). This tendency may be present in some uses, but intensity, deliberate intent, or sin should not be inferred from it in every instance.

8. Kasb and Personal Responsibility

Numerous ayahs employing K S B emphasize the principle that each person’s action becomes attributable to that person.

Al-Anam states:

وَلَا تَكْسِبُ كُلُّ نَفْسٍ إِلَّا عَلَيْهَا

Wa-lā taksibu kullu nafsin illā ʿalayhā.

No soul acquires anything except against itself.

Al-Anam 6:164

The same ayah then says:

وَلَا تَزِرُ وَازِرَةٌ وِزْرَ أُخْرَىٰ

Wa-lā taziru wāziratun wizra ukhrā.

No bearer of burdens bears another’s burden.

The juxtaposition of these two sentences shows that kasb is connected with individual responsibility. What a person acquires is attributed to them, and someone else’s burden does not take its place.

This meaning recurs in:

لَهَا مَا كَسَبَتْ

Lahā mā kasabat.

and:

كُلُّ نَفْسٍ بِمَا كَسَبَتْ رَهِينَةٌ

Kullu nafsin bi-mā kasabat rahīnatun.

as well.

One Qur’anic axis of this root is therefore attributing the outcome of an action to its agent.

9. Economic Usage Remains Part of the Root

Although the Qur’an takes the field of kasb far beyond wealth, its economic meaning also remains.

Al-Baqarah states:

أَنفِقُوا مِن طَيِّبَاتِ مَا كَسَبْتُمْ

Anfiqū min ṭayyibāti mā kasabtum.

Spend from the good things you have acquired.

Al-Baqarah 2:267

In Al-Masad:

مَا أَغْنَىٰ عَنْهُ مَالُهُ وَمَا كَسَبَ

Mā aghnā ʿanhu māluhu wa-mā kasaba.

His wealth and what he acquired did not avail him.

Al-Masad 111:2

In such contexts, wealth, possessions, or the yield of worldly activity can be instances of kasb.

It is therefore wrong to sever “kasb” from its economic meaning, just as it is wrong to restrict all its uses to economics.

10. Comparison with Nearby Roots

K S B (كَسَبَ, Kasaba) and AYN M L (عَمِلَ, ʿAmila)

ʿAmal more directly indicates the doing of the action itself.

Kasb places greater emphasis on what the person obtains through that action and what is attributed to them.

Concisely:

ʿAmal is the action itself; kasb is the outcome and attribution of that action to its agent.

This distinction is a tendency, not an absolute boundary. In many ayahs, the fields of the two words draw close.

K S B (كَسَبَ, Kasaba) and S AYN Y (سَعَى, Saʿā)

Saʿy emphasizes effort and movement toward a goal.

Kasb places greater emphasis on obtaining something.

A person can strive for something without reaching it; kasb usually includes a degree of attainment and attribution.

K S B (كَسَبَ, Kasaba) and A KH DH (أَخَذَ, Akhadha)

Akhdh is taking. Something can be taken without the person having produced it through their own effort or action.

Kasb has a closer relationship with the person’s own pursuit, action, or activity.

Every kasb is a kind of obtaining, but not everything a person takes is necessarily their kasb.

11. From Qur’anic Meaning to the Theological Term “Kasb”

In the centuries after the Qur’an, kasb became a technical theological term in disputes over human freedom and the creation of acts.

One of the best-known forms of this discussion later developed in the Ashʿari school. This theory distinguished “creating an act” from “acquiring an act”: the act was attributed to The God in respect of its creation, while the human being was related to it through acquisition, in order to explain human responsibility.

Nevertheless, the theological concept of kasb had already been discussed among some theologians before Abu al-Hasan al-Ashʿari, and its emergence should not be restricted to a single person.

This history matters for understanding the term’s development, but Qur’anic kasb should not be defined by Ashʿari theological theory. Centuries before these theological systems took shape, the Qur’an used K S B in the natural sense of acquiring, obtaining, and attributing action to human beings.

Later theories were attempts to explain philosophical and theological questions using this word. They should not be projected backward to determine the meaning of the ayahs.

12. Challenges in Understanding and Translation

The first error is restricting kasb to money and income. A large proportion of Qur’anic uses concern actions and their outcomes.

On the other hand, كَسَبَ (kasaba) should not be translated simply as “did” wherever it appears. In many ayahs, the relationship of the action to its outcome and the person to whom it belongs is part of the meaning.

Nor should the difference between كَسَبَ (kasaba) and اكْتَسَبَ (iktasaba) become a rule of “good versus evil.” An-Nisa 4:32 clearly limits that rule. Al-Raghib’s proposed distinction—that kasb is broader, while iktisāb is more specific to what a person obtains for themselves—is more defensible linguistically, but it too must be assessed against the context in each ayah.

The Qur’an’s network of trade, gain, and loss should likewise not become the lexical definition of kasb. The Qur’an uses marketplace language to explain many human choices, but K S B itself had an independent meaning before these metaphorical uses.

The ayahs concerning calamity and corruption should not become a theory describing every natural disaster or individual illness as direct punishment for the person’s sin. That conclusion does not follow from the root.

Finally, the later theological term “kasb” should remain distinct from Qur’anic usage. Ashʿari theory belongs to the history of how this word has been understood, rather than constituting its definition.

13. Suggested Translations for Forqan

كَسَبَ (kasaba):
“Acquired,” “gained,” “obtained,” according to context.

كَسَبَ سَيِّئَةً (kasaba sayyiʾatan):
“Acquired an evil deed”;
or “obtained an evil deed for themselves.”

لَهَا مَا كَسَبَتْ (lahā mā kasabat):
“For it is what it has acquired.”

وَلَكُم مَّا كَسَبْتُمْ (wa-lakum mā kasabtum):
“And yours is what you have acquired.”

بِمَا كَسَبَتْ قُلُوبُكُمْ (bi-mā kasabat qulūbukum):
“For what your hearts have acquired.”

بِمَا كَسَبَتْ أَيْدِيكُمْ (bi-mā kasabat aydīkum):
“Because of what your hands have acquired.”

مِّمَّا كَسَبُوا (mimmā kasabū):
“Of what they have acquired.”

اكْتَسَبَ (iktasaba):
“Acquired for themselves,” “gained,” or “obtained,” according to context.

This verb should not always be rendered as “committed,” since not all of its uses are negative.

مَا اكْتَسَبَ مِنَ الْإِثْمِ (mā iktasaba mina al-ithm):
“What they acquired for themselves of sin.”

مِّمَّا اكْتَسَبُوا / مِّمَّا اكْتَسَبْنَ (mimmā iktasabū / mimmā iktasabna):
“Of what men have acquired for themselves / of what women have acquired for themselves.”

مِن طَيِّبَاتِ مَا كَسَبْتُمْ (min ṭayyibāti mā kasabtum):
“From the good things you have acquired.”

Conclusion

The root K S B in Arabic denotes seeking, acquiring, and obtaining something. Wealth and provision were among its early uses, but from the outset the root was not restricted to economic income.

The Qur’an takes this capacity into a much broader field. A person can acquire wealth, but can also acquire good or evil; their heart acquires something, their hands obtain something for them, and every soul faces what it has acquired.

Kasb in the Qur’an therefore often connects action with the outcome attributed to its agent. This feature brings personal responsibility to the fore in many ayahs employing this root.

Kasb and iktisāb are not completely identical, but their difference should not be reduced to good and evil. Al-Raghib al-Isfahani considers kasb broader: a person can acquire for themselves or for another; iktisāb concerns more particularly what they obtain for themselves. This difference is more consistent with Qur’anic usage than the simple rule “kasb for good and iktisāb for evil.”

The Qur’an also places kasb within a network of concepts of gain and loss. Guidance and misguidance can be exchanged like goods, trade can yield profit or perish, and people ultimately face the outcome of their choices. This network enriches the picture of kasb, but is not its lexical origin.

In later periods, this same capacity of the word to attribute action and outcome to human beings made “kasb” an important term in debates over determinism and free will, especially prominent in Ashʿari theology. This later usage belongs to the word’s history, rather than being a meaning that should be projected back onto the Qur’anic ayahs.

A cautious account of the root is:

K S B: seeking and obtaining something that becomes attributable to the agent; and, in Qur’anic usage, acquiring action, good, evil, or an outcome that stands for or against a person. Iktisāb is a more specific branch that can emphasize what a person obtains for themselves, but neither form has a fixed moral value in itself.