The other tier, by contrast, functions as a commentary on the first. In it I trace every ḥadith mentioned in the upper tier, exhaustively gathering its various wordings and transmission routes. I then examine their chains of transmission and corroborating narrations, grading the narrators and the reports—declaring them reliable or unreliable, authentic or weak—in accordance with the science of ḥadith and its established principles.

It often happens that a particular chain preserves phrases or additions not found in the others. Whenever such variants can be harmonized with the parent text, I incorporate them into the ḥadith cited in the upper section, enclosing them in square brackets like this: [ ], without specifying which collector has uniquely preserved them. This procedure is followed when the report ultimately goes back to the same Companion; if, however, it originates with a different Companion, I treat it as a separate entry, as you will notice in the section on the opening supplications and elsewhere. This is a rare and valuable feature—hardly to be found in another book. All praise is for Allah; by His grace good works reach completion.

Next, I set out the positions of the jurists regarding the ḥadith under discussion, present the evidence each of them cites, analyze those proofs, and clarify the strengths and weaknesses of every view. From this evaluation we distil the conclusion I have placed in the upper tier. I may also touch on certain issues for which no explicit textual evidence exists in the Sunnah—matters that rest on scholarly reasoning—although such topics lie beyond the main purpose of this book.

I ask Allah, may He be exalted, to make this work purely for His noble countenance and to grant benefit through it to my fellow believers. He is indeed the All-Hearing, the Responsive.