The Messenger of Allah ﷺ said, "The likeness of my nation is that of the rain. It is not known whether its beginning is better or its end."
قال رسول الله ﷺ: مثل أمتي مثل المطر، لا يدرى أوله خير أم آخره.
Bazzar (1412) and Ibn Hibban (7226) both narrated it through the route of Fudayl bin Sulayman, who said, Musa bin Uqba narrated to us, from Ubayd bin Sulayman Aghar, from his father, from Ammar bin Yasir, and he mentioned it. Fudayl bin Sulayman is Numayri, about whom the scholars have spoken critically, and he is daif in hadith. However, the hadith has another chain that strengthens it.This is what Ahmad (18881) narrated from Abdul-Rahman bin Mahdi, who said, Ziyad Abu Umar narrated to us, from Hasan, from Ammar bin Yasir, with the same wording. This chain is disconnected, because Hasan Basri was a mudallis and narrated using "an" without specifying direct hearing, and he did not hear from Ammar bin Yasir.It has yet another chain. Tayalisi (682) narrated it from Imran, who is Qattan, from Qatada, who said, a companion of ours narrated to us, from Ammar, and he mentioned it. The narrator from Ammar is unknown.Through these routes, the hadith rises to the level of hasan, Allah willing. On this subject there are other hadiths in the musnads of Imran bin Husayn, Abdullah bin Umar, and Abdullah bin Amr bin As, and each of them has some issue.The hadith should be understood as referring to those who came after "the best generations," who are explicitly named in the sahih hadiths, and who are without doubt the best of this nation. So this hadith must necessarily be understood as referring to someone other than them.Ibn Hibban said, "The general address here is meant for some of the nation, not all of it."Alai said, "The established hadiths on the superiority of the companions over those who came after them are explicit and admit no other interpretation, and they are more sahih and more numerous than these hadiths which allow for interpretation, so they cannot be considered contradictory to them."What he said here is the truth, and the exception I mentioned is necessary in order for the meaning of the two hadiths to be reconciled properly. This hadith is counted among the signs of prophethood, for reality itself bears witness to it.