The cause of their disagreement here is identical to the cause of their disagreement over the distance that allows the shortening of prayer, even though that latter question admits of a more general ruling. Shortening (qaṣr) has been handed down by both explicit statements and actual practice, whereas combining (jamʿ) has come to us through practice alone. Consequently, whoever limited the ruling to the very type of journey in which the Messenger of Allah—may Allah bless him and grant him peace—actually combined would not permit it in any other, whereas whoever understood the incident to signal a concession for travellers in general extended the licence to every lawful journey.

As for combining while at home with no recognized excuse, Mālik and the great majority of jurists do not allow it. By contrast, a number of the Zahiri scholars—and Ashhab among Mālik’s own companions—deemed it permissible.

The root of their dispute lies in how they understood the ḥadīth of Ibn ʿAbbās. Some, following Mālik, interpreted it as having taken place because of rain, while others acted upon its outward, unrestricted wording. Muslim relates an additional phrase in this narration in which the Prophet—peace and blessings be upon him—combined "not out of fear, nor on a journey, nor because of rain." On the strength of this wording the Zahiris held fast to the hadith in its unqualified form.

Combining in non-travel situations specifically on account of rain is another point of divergence. Al-Shāfiʿī allows it, whether by day or by night. Mālik forbids it in the daytime but permits it at night, and he extends the licence to night-time mud as well, even without actual rainfall.

Al-Shāfiʿī reproached Mālik for distinguishing between daytime and nighttime prayers, arguing that Mālik himself had transmitted the hadith yet restricted its general import by analogy. Mālik had commented on Ibn ʿAbbās’s words—"The Messenger of Allah, may Allah bless him and grant him peace, combined ẓuhr with ʿaṣr and maghrib with ʿishāʾ in neither fear nor travel"—by saying, "I believe that was because of rain." Thus he neither adopted the hadith in its full generality nor interpreted it consistently; rather, he rejected part of it and construed part of it—a course of action impermissible by unanimous agreement. Specifically, he set aside the portion that says "he combined ẓuhr with ʿaṣr," yet accepted and interpreted the words "and maghrib with ʿishāʾ."

I suspect—Allah have mercy on him—that Mālik discarded part of the report because established practice opposed it; he therefore retained only the segment to which no practice was contrary, namely combining maghrib and ʿishāʾ in residence, as related from Ibn ʿUmar: whenever the governors combined those two prayers, he would combine with them. Yet whether such communal practice can serve as a legal proof is itself debatable. Early Mālikī masters regarded it as a form of consensus, which is untenable, for the agreement of merely some scholars is not authoritative. Later Mālikīs considered it a form of mass transmission (tawātur), supporting their claim by citing the ṣāʿ-measure and other matters passed down in Medina generation after generation. But practice is an act, and an act does not yield tawātur unless it is accompanied by explicit report, for tawātur is established through narration, not action. Indeed, to make deeds alone produce tawātur is difficult—perhaps even impossible. What seems more plausible to me is that this appeal to communal practice resembles Abū Ḥanīfa’s principle of “prevalent necessity” (ʿumūm al-balwā), for it is inconceivable that