(1) Muhammad ibn Thabit al-Abdi, Abu Abd, a Basran. Al-Hafiz (Ibn Hajar) rates him “weak” in his Taqrib, and the author states in al-Mizan that more than one critic judged him “not strong.” The hadith is recorded in the Musnad 1/284-285 through Muhammad ibn Thabit with the same chain, except that Kuraib is omitted. The report also reaches us through other sound chains from Ibn Abbas, both in extended and abridged form, in the Musnad 1/242, 282, 284; Sahih al-Bukhari nos. 117, 138, 697, 698, 699, 726, 728, 859, 1198, 4569, 4571, 4572, 5919, 6215, 6316, 7452; Sahih Muslim no. 763/181-193; Muwatta Malik 1/121; Sunan Abi Dawud nos. 58, 610, 611, 1353-1358, 1364, 1365, 1367; and al-Nasaʾi 2/30, 218; 3/210, 236. Ibn al-Athir has gathered the narrations found in the Six Books in Jamiʿ al-Usul 6/80-90. (2) This is the collection known as the “Forty of Ibn Wadʿan.” Ibn Hajar reports in Lisan al-Mizan 5/306 that when al-Mizzi was asked about it he replied, in summary: none of the forty is sound as presented with those isnads; only a few phrases are authentic with familiar chains, and tracing them would require leisure. Moreover, the whole work is plagiarised: Ibn Wadʿan stole it from Zayd ibn Rifaʿa—also said to be Zayd ibn Abd Allah ibn Masʿud ibn Rifaʿa al-Hashimi—who is credited with authoring the “Epistles of the Brethren of Purity,” was ignorant of hadith, and himself fabricated the booklet. Ibn Wadʿan then attached invented isnads, sometimes via a single intermediary from Ibn Rifaʿa’s shaykh, sometimes by inserting two narrators; most of them are unknown, and the existence of some is doubtful. In short, the work is an outright forgery. Ibn al-Jawzi adds in al-Muntazam 9/127 that Ibn Wadʿan reached Baghdad in 373 AH carrying a fascicule of forty hadith from his uncle Abu al-Fath. These were the very pieces fabricated by Zayd ibn Rifaʿa al-Hashimi; Abu al-Fath stole them, removed their preface, and attached to each hadith a chain ending with the shaykh from whom Ibn Rifaʿa claimed narration.