Jami` at-Tirmidhi 3640
جامع الترمذي#3640SahihNarrated Anas bin Malik:that the Messenger of Allah (ﷺ) would repeat a statement three times so that it could be understood
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Ahmad Muhammad ShakirHasan Sahih
Al-AlbaniHasan Sahih
Bashar Awad MaaroufHasan Sahih
Zubair Ali ZaiSahih
In-book reference: 49:36