Jami` at-Tirmidhi 687
جامع الترمذي#687Da'ifAbu Hurairah narrated that :the Messenger of Allah said: "Count the (the appearances of) the crescent of Sha'ban for Ramadan
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Ahmad Muhammad ShakirHasan
Al-AlbaniHasan
Zubair Ali ZaiDaif
In-book reference: 8:6