Dr. M. Ibrahim Faaris, in his book صفوة الراسخ في علم المنسوخ والناسخ, page 42, talks about the type of abrogation of both text and ruling. He says that Judge Abu-Bakr has reported that some scholars have rejected that type of abrogation because all narrations about it are singles, and they asserted that no decision on revelation of a verse or abrogation thereof can be made using a single narration chain, because that is an uncertain evidence (ظني).
He says that Dr. Mannaa` Al-Qattaan, in his book مباحث في علوم القرآن, pages 238-240, answered that by saying that proving revelation is different from proving abrogation. The former must be with certain, ubiquitous narration, but the latter may be with less than ubiquitous text.
Huh? When was that rule established? By what authority? Didn't scholars already agree, as shown in the previous post
, that the abrogator must be equal in authenticity or exceeds that of the abrogated?