Introduction

The science of Islamic inheritance law, known in Arabic as ʿilm al-farāʾiḍ, occupies a unique place in the Shariʿah. The Prophet Muḥammad, peace be upon him, described it as half of all knowledge and urged the Muslims to learn it and teach it, warning that it would be among the first branches of learning to be forgotten. The Quran devotes more detailed legislative text to inheritance than to any other single legal topic, specifying fixed fractional shares for a range of heirs across three consecutive verses in Sūrat al-Nisāʾ. Modern works on Islamic will and inheritance law in English, including those by scholars such as Muḥammad Iqbāl Siddiqi, have aimed to make this technically demanding science accessible to Muslims living in Western legal contexts, where the intersection of Islamic inheritance rules with civil probate law creates distinctive practical challenges.

Works in this genre typically cover the subject across three interconnected domains. The first is the law of waṣiyyah, the Islamic will, including the condition that a bequest to a non-heir may not exceed one third of the net estate, and the rulings on who may validly execute and witness such a document. The second is the body of farāʾiḍ rulings themselves: the six standard fractional shares (one half, one quarter, one eighth, two thirds, one third, and one sixth), the categories of heirs who receive fixed shares (aṣḥāb al-furūḍ), those who inherit the residue (ʿaṣabah), and those who are excluded by closer relatives (maḥjūbūn). The third domain addresses the rules of ḥajb (exclusion) and radd (return of surplus shares), as well as special cases such as the inheritance rights of spouses, the child born of a valid marriage, and heirs of different religions.

The scholarly importance of accessible English treatments of al-farāʾiḍ cannot be overstated for Muslim minorities in the West. Muslims who die without an Islamically valid will risk having their estates distributed according to civil intestacy law, which does not recognize the fractional shares prescribed by the Quran. A growing body of modern scholarship has worked to bridge this gap by explaining how Muslims can use civil legal instruments such as wills and trusts to approximate the distribution mandated by the Shariʿah, and by clarifying the obligatory nature of ensuring that one's estate is managed in accordance with divine command. Works in this area draw on the classical manuals of all four Sunni schools, with particular reliance on the Ḥanafī texts of the Indian subcontinent tradition and the Mālikī and Shāfiʿī works that are authoritative across Muslim-majority regions.

Readers approaching a work on Islamic will and inheritance law should prepare to engage with a subject that requires careful, patient study. The mathematics of fractional share distribution, particularly in complex estates with multiple classes of heirs, benefit from working through numerical examples methodically rather than reading the rules abstractly. Readers are advised to identify the category of each potential heir in their own family before applying the rules, and to consult a qualified Islamic scholar or a solicitor with expertise in Islamic estate planning when drafting an actual will. This subject, though technical, is one of the most important areas of religious obligation that Muslims in any era can fulfil, and familiarity with its principles is an act of worship in its own right.