"Among all disciplines of Islamic jurisprudence (Fiqh), the science of inheritance holds a singular distinction: Allah did not entrust its apportionment to an angel brought near or a prophet sent, but ordained the exact fractional entitlements Himself directly in His Book." — Imam Siraj al-Din al-Sajawandi, Al-Sirajiyyah
Throughout the vast landscape of Islamic sacred law—whether in commercial contracts (Mu‘āmalāt), judicial procedure (Qaḍā’), or governance (Siyāsah Shar‘iyyah)—the Quran generally lays down overarching moral imperatives and ethical frameworks, leaving detailed applications to the scholarly deduction (Ijtihād) of jurists.
Inheritance law (‘Ilm al-Farā’iḍ) is the monumental exception. Here, Allah Subhanahu wa Ta'ala revealed specific arithmetical fractions (1/2, 1/4, 1/8, 2/3, 1/3, 1/6), designated precise familial beneficiaries, defined exclusion mechanisms, and sealed the legislation with the solemn warning: تِلْكَ حُدُودُ اللَّهِ ("These are the limits set by Allah..." — Surah An-Nisa 4:13). The Prophet Muhammad (ﷺ) declared it "half of all knowledge" (Sunan Ibn Majah 2719).
1. The Dark Ages of Succession: Pre-Islamic Arabia (Al-Jāhiliyyah)
In the Arabian Peninsula prior to the advent of Islam, the distribution of wealth was governed by a brutal tribal survival ethic:
"Lā yarithunā illā man yaḥmilu al-sayf wa yaṭ‘anu bi’l-rimāḥ wa yaḥūzu al-ghanīmah"
"None shall inherit from us except he who bears the sword, thrusts with the spear, and captures the war-spoils."
Under this martial code, inheritance was restricted exclusively to mature, adult warrior men. Women of all ages, infant boys, elderly disabled men, and orphans were completely barred from inheriting.
Worse still was the treatment of surviving widows. In pre-Islamic tradition, when a married man died, his agnatic heirs (brothers, cousins, or sons from another wife) would rush to cast a garment over the widow. By doing so, they established proprietary ownership over her person: they could either force her to marry one of them without a new Mahr, marry her off to an outsider and pocket the bridal gift themselves, or lock her away until she agreed to buy her freedom with her deceased husband’s wealth.
The Occasion of Revelation (Asbāb al-Nuzūl)
When Aws ibn Thabit al-Ansari passed away leaving a widow (Umm Kujjah) and two small daughters, his paternal cousins seized his entire property, palm orchards, and livestock. When Umm Kujjah cried to the Prophet (ﷺ) that her daughters were destitute and without support, Allah revealed the revolutionary decree:
لِّلرِّجَالِ نَصِيبٌ مِّمَّا تَرَكَ الْوَالِدَانِ وَالْأَقْرَبُونَ وَلِلنِّسَاءِ نَصِيبٌ مِّمَّا تَرَكَ الْوَالِدَانِ وَالْأَقْرَبُونَ مِمَّا قَلَّ مِنْهُ أَوْ كَثُرَ ۚ نَصِيبًا مَّفْرُوضًا
"For men is a share of what the parents and close relatives leave, and for women is a share of what the parents and close relatives leave, be it little or much—an obligatory share." (Surah An-Nisa 4:7)
2. The Companions (Ṣaḥābah): Masters of the Divine Math
Following the Prophet’s (ﷺ) passing, novel succession scenarios arose as Muslim society expanded across Persia, the Levant, and North Africa. Four prominent companions laid the jurisprudential bedrock of Ilm al-Faraid:
"The most knowledgeable of my Ummah regarding inheritance is Zayd ibn Thābit." — Prophet Muhammad (ﷺ) (Jami' at-Tirmidhi 3790)
Zayd served as chief judicial arbiter of Faraid under Caliphs Abu Bakr, Umar, and Uthman. He systematized the rules of agnatic substitution, the shares of grandmothers, and the intricate formulas governing grandfather competing with siblings (Al-Jadd ma‘a al-Ikhwah). His methodology forms the primary basis of the Shafi'i and Hanbali schools.
The Great Systematizer & Innovator of Consensus (Ijmā‘)
Umar resolved the first historical estate deficit by convening the Sahaba to establish Al-‘Awl (proportional fraction reduction), preventing any Quranic heir from complete disinheritance. He also formulated the landmark Al-‘Umariyyatān solution for parents and spouses.
The Pulpit Verdict: Al-Mas’alah al-Minbariyyah
While delivering a Friday sermon from the minbar of Kufa, Ali was interrupted with an inheritance query: Wife, Two Daughters, and Both Parents. Without pausing his sermon, Ali answered in real-time rhyme: "Sāra thumnuhā tus‘an" ("Her eighth has become a ninth!"), instantly resolving the denominator expansion from 24 to 27.
Master of Kufan Jurisprudence
Pioneered the legal doctrine of Al-Radd (returning surplus estate funds to blood Quranic sharers when no residuary exists). His legal decisions formed the structural cornerstone of the Hanafi school of law.
3. How Islamic Faraid Gave Birth to Modern Algebra
One of the greatest milestones in world intellectual history is the direct link between Islamic inheritance jurisprudence and the invention of Algebra.
In the 9th century, in the House of Wisdom (Bayt al-Ḥikmah) in Baghdad, the Persian mathematician Al-Khwarizmi authored his seminal book: Al-Kitāb al-mukhtaṣar fī ḥisāb al-jabr wa’l-muqābalah (The Compendious Book on Calculation by Completion and Balancing)—from whose title the word "Algebra" is derived.
Thus, Western mathematics, computing algorithms, and modern algebra were born directly from the spiritual imperative to calculate Islamic inheritance accurately!
4. Classical Didactic Treatises: Matn al-Raḥbiyyah & Al-Sirājiyyah
Over the centuries, Muslim scholars condensed the mathematical and legal rules of Faraid into poetic didactic manuals (Mutūn) designed for memorization:
Matn al-Raḥbiyyah (Bughyat al-Bāḥith)
By Imam Muhammad ibn Ali al-Rahbi (d. 577 AH / 1181 CE)A masterwork of 175 rhyming poetic verses in the Rajaz meter covering every fundamental rule of Quranic shares, residuaries, blocking (Hajb), Awl, and kinship calculation. For eight centuries, it has remained the standard memorization curriculum across Al-Azhar, Mecca, and madrasas worldwide.
Al-Farā’iḍ al-Sirājiyyah
By Siraj al-Din Muhammad al-Sajawandi (d. 600 AH / 1204 CE)The gold-standard treatise in Hanafi estate mathematics. Translated into English by Sir William Jones in 1792 for the British administration in Bengal, it represents one of the most comprehensive analytical treatments of fractions, common denominators, and distant kindred (Dhawū al-Arḥām).
5. Consensus and Nuanced Divergence Across the 4 Madhhabs
The Four Sunni Schools of Law (Hanafi, Maliki, Shafi'i, and Hanbali) share universal consensus (Ijmā‘) on more than 90% of inheritance rules. The areas of divergence represent scholarly precision in interpreting ambiguous scenarios:
| Juristic Issue | Hanafi View | Shafi'i & Maliki View | Hanbali View |
|---|---|---|---|
| Grandfather with Siblings | Grandfather completely excludes all brothers and sisters (Ruling of Abu Bakr). | Siblings share with grandfather via Muqāsamah (Ruling of Zayd ibn Thabit). | Siblings share via Muqāsamah up to a 1/6 or 1/3-remainder floor. |
| Surplus Return (Al-Radd) | Returned proportionally to blood Quranic sharers (excludes spouses). | Historically escheats to Bayt al-Māl; later Shafi'is adopted Radd. | Returned proportionally to blood Quranic sharers. |
| Distant Kindred (Dhawū al-Arḥām) | Inherit in the absence of fixed sharers and residuaries. | Historically do not inherit (wealth to Bayt al-Māl); later jurists allowed. | Inherit via Tanzīl (stepping into shoes of linking heir). |