to al-Tha'labī is not proof, by agreement of Sunnis and Shia. Not every report narrated by a member of the majority is thereby authoritative in the eyes of the majority. Rather, the scholars (1) of the majority agree that reports narrated by al-Tha'labī and others like him are not accepted as proof—whether concerning the merits of Abu Bakr and Umar or the establishment of any legal ruling—unless their authenticity is established by some valid means (2).
He therefore cannot say, “We invoke against you the hadiths narrated by [one of] the majority (3).” This is like someone saying, “I will judge against you on the testimony of anyone from the majority who testifies (4) against you.” Does any scholar of the majority maintain that everyone among them who has testified (5) is upright? Or has (6) any of their scholars said, “Every hadith narrated by one of them (7) is authentic”?
Moreover, (8) the scholars of the majority agree that al-Tha'labī and others like him narrate both authentic and weak reports. They also agree that the mere fact that he narrates something does not require it to be accepted. Hence they say of al-Tha'labī (9) and others like him that he is like someone gathering firewood in the dark: he relates whatever he finds, whether sound or unsound. Thus, although most of the hadiths in his commentary are authentic, it also contains reports that all qualified scholars agree are fabricated lies.