Weak hadiths- part 1.
(A:) Weak (da’if) is a term for any hadith with a chain of transmission containing a narrator whose memory was poor, one who was not trustworthy, not identified by name, or for other reasons. But weak cannot simply be equated with false. Were this the case, mere analysis of transmitters would be the universal criterion for acceptance or rejection of particular rulings based on hadith. While scholars do use this measure in upgrading the work of preceding generations of legal authorities, they have not employed it as a simplistic expedient to eliminate every piece of legal information that is connected with a weak hadith, because of various considerations.
Multiple means of transmission
One of these is that when a piece of information is received through a means of transmission that or may not be trustworthy, we generally have doubts about it. But when one and the same piece of information reaches us through several completely different channels, even though each one may or may not e trustworthy, the logical probability of the information’s falsity is much reduced. And if we receive the very same piece of information from ten such channels, the possibility of its falsity does not usually even come to mind.
This verificatory principle has two important implications, one being the obligatory nature of belief in hadith that are mutawattir, and the second being the weight that hadith scholars give to multiple means of transmission, which can raise a hadith from well authenticated (hasan) to rigorously authentic (sahih), or from weak (da’if) to well authenticated, as described in the following account of a hadith’s reclassification by a major specialist in hadith forgeries.
(‘Ali Qari:) The hadith “ I am the city of knowledge and ‘Ali is its gate,” was mentioned by Tirmidhi in his Jami’, where he said is was unacknowledgeable. Bukhari also said this, and said it was without legitimate claim to authenticity. Ibn Ma’in said it was a baseless lie, as did Abu Hatim and Yahya ibnu Sa’ad, Ibn Jawzi recorded it in his book of hadith forgeries, and was confirmed by Dhahabi and others in this. Ibn Daqiq al-‘Eid said, “This hadith is not confirmed by scholars, and is held by some to spurious.” Daruquthni stated that it was uncorroborated. Ibn Hajar ‘Asqalani was asked about it and answered that it was well authenticated (hasan), not rigorously authenticated (sahih), as Hakim had said, but not a forgery (mawdu’) as Ibn Jawzi had said. This was mentioned by Suyuti. The hadith master, (hafiz) Abu Sa’id ‘Ala’I said, “the truth is that the hadith is well authenticated (hasan), in view of its multiple means of transmission, being neither rigorously authenticated(sahih) nor weak (da’if), much less a forgery” (Risala al-mawdu’at(y112),26).