Kitab as-Salah and Kitab az-Zakat

The prayer and zakah sections of Sunan Abu Dawud are among the most legally detailed in the collection and have served as primary sources for jurists across all four schools for over a millennium. Abu Dawud's characteristic approach — including not only the strongest narrations but those that address contested sub-questions — makes these sections richer in juristic material than the corresponding sections of the two Sahihs.

Kitab as-Salah opens with chapters on the adhan and iqamah, covering the wording in detail and addressing the question of whether the iqamah should be said in pairs (as the Shafi'i and Maliki schools hold) or singly (as the Hanafi school holds). The competing narrations on this question sit in close proximity in Abu Dawud's arrangement, and later commentators worked through the chains of each to determine which was more strongly authenticated.

The chapters on the prayer itself cover every integral and sunnah element in a sequence that moves from the opening takbir through the closing salam. Abu Dawud's section on the opening supplication (dua al-istiftah) is notable: he records multiple variant formulas that the Prophet used at different times, allowing jurists to understand that while there is a sunnah opening supplication, several authenticated forms exist and the question of which is most recommended can be answered by weighing chains.

The Friday prayer chapters are extensive. Abu Dawud covers the obligation of Friday prayer, who it applies to (residents, not travelers), the number of khutbahs and their conditions, the time window for the prayer, and the disputed question of whether Friday prayer requires a minimum community size. He also records hadiths on the virtue of the Friday prayer, the hour of acceptance within it, and the recommended conduct of those attending.

The prayer of fear, eclipse prayer, rain prayer, Eid prayers, and the voluntary night prayers all receive dedicated chapters with more detailed coverage than the two Sahihs provide. The night prayer (tahajjud) section includes hadiths on the number of units the Prophet prayed, the witr prayer and its forms, and the practice of qunut supplication in witr — a question on which the schools differ significantly.

Kitab az-zakah opens with the hadiths establishing zakah as one of the five pillars and moves through the nisab (minimum threshold) and rates for each category of zakatable wealth: gold, silver, livestock (camels, cattle, sheep), agricultural produce, and trade goods. Abu Dawud's treatment of livestock zakah is exceptionally detailed, preserving the letter of Abu Bakr to Anas ibn Malik specifying the exact rates for different numbers of camels, cattle, and sheep — a document that became the standard reference for livestock zakah calculations.

The chapters on zakah al-fitr — the obligatory charity at the end of Ramadan — record the quantities required, the eligible recipients, and the timing of its payment. The question of whether zakah al-fitr may be paid in cash or only in food is one of the most debated in Islamic finance, and the relevant hadiths in Abu Dawud's Sunan are central to that debate. His inclusion of narrations on both sides, without dogmatically favoring one, illustrates the evenhanded approach that has made the Sunan a reference across madhab boundaries.