Kitab an-Nikah and Kitab al-Janaiz

The marriage and funerary rites sections of Sunan an-Nasai preserve hadiths on two domains that touch the most pivotal moments of a Muslim's life — entering a family and leaving the world — and an-Nasai's characteristic rigor in these sections makes them essential references for Islamic family law and the law of death and burial.

Kitab an-Nikah opens with the hadiths urging marriage and describing its spiritual and social benefits. An-Nasai then moves through the conditions of a valid marriage with particular attention to the role of the guardian (wali). The famous hadith 'There is no marriage without a guardian' appears in an-Nasai's collection with chains that he considers sound, and his treatment of the question of which women require guardians and under what circumstances a guardianship may be delegated is among the most detailed in any collection.

The mahr (bridal gift) chapters are thorough. An-Nasai records hadiths establishing that the mahr may be as small as an iron ring or even the teaching of Quran, and others indicating that it should not be excessively inflated to the point of discouraging marriage. The Prophet's own mahar practices for different wives are recorded, and the hadiths establishing that excessive mahr is contrary to the spirit of ease in marriage were cited extensively by scholars concerned about social practices that made marriage financially inaccessible.

The chapters on the prohibited degrees of marriage — the women a man may never marry — are organized as a taxonomy drawn from the Quranic verse on mahrams and the hadiths that extend or specify its provisions. An-Nasai's treatment includes hadiths on fosterage (rada'ah) and the prohibition of marriage between foster siblings, with details on the minimum amount of nursing that creates the prohibition. This question — whether a single feeding is sufficient or whether a minimum number of feedings is required — was debated among the schools, and the hadiths an-Nasai preserves on it were central to the debate.

Kitab al-Janaiz — the Book of Funerary Rites — is one of an-Nasai's most important contributions to the practical literature on death and burial. The section begins with hadiths on visiting the sick, the etiquette of being present at the moment of death, and the instruction to close the deceased's eyes. It then covers in sequence every stage of the funerary process: washing the body, shrouding it, the funerary prayer (salah al-janazah), carrying the bier, and burial.

The chapters on the funerary prayer are extensive. An-Nasai records multiple hadiths on the number of takbirs (the majority opinion is four), the recitations within each section, the supplication for the deceased, and the conditions for validly praying the funerary prayer. His coverage of the prayer in absentia (salah al-gha'ib) — praying the funerary prayer over someone who has died and been buried elsewhere — is particularly valuable, with narrations establishing that the Prophet prayed over the Negus of Abyssinia in his absence.

The burial chapters cover the depth and orientation of the grave, the prohibition of building structures over graves or plastering them (a hadith that became the basis for scholarly positions on grave veneration), and the hadiths on visiting graves. An-Nasai's strict chains for the prohibition of building over graves made his Sunan an important reference for scholars arguing against dome construction over burial sites — a recurring debate across Islamic history. His collection of hadiths on visiting graves for remembrance of death, without the innovations that some scholars condemned, represents the tradition's effort to maintain a balanced position between two extremes.