by hadith masters in dedicated works, such as the hadith master Abū Muhammad al-Khallāl and others. They also know that the transmitted hadiths(1) concerning the merits of the Opening of the Book, the Throne Verse, the closing verses of al-Baqarah, and the two surahs of refuge are authentic. Thus, they possess a criterion by which they distinguish truth from falsehood.

As for the (hadiths)(2) concerning the occasions of revelation, most are reported without complete chains rather than through fully connected chains. This is why Imam Ahmad ibn Hanbal said:

“Three branches of knowledge have no chains of transmission”—or, in another wording, “have no basis”: Quranic exegesis, accounts of military campaigns, and accounts of the great battles to come.

By this he meant that the hadiths in these fields have incomplete chains.

Scholars have differed over whether disconnected reports should be accepted or rejected. The soundest view is that some are accepted, some are rejected, and judgment on others is suspended. If someone is known to transmit in this way only from a trustworthy narrator, his disconnected report is accepted. If someone is known to transmit from both trustworthy and untrustworthy narrators, his omission amounts to reporting from someone whose standing is unknown; judgment on his report is therefore suspended. Any disconnected report that conflicts with what trustworthy narrators have related is rejected.

When a disconnected report comes through two routes(3), each of the two narrators(4) having learned from the teachers of the other(5), this is among the considerations(6) indicating its truth. For if, in a case of this kind, it is ordinarily inconceivable that identical error or deliberate fabrication could account for both transmissions, the report is known to be true; for a reporter can go wrong(7) only through (deliberate lying or through)(8)