Jami` at-Tirmidhi 1029
جامع الترمذي#1029SahihAishah narrated that:The Prophet said: "No one among the Muslim dies, and Salat is performed for him by a community of Muslims reaching one hundred, and they intercede (supplicate) for him, except that their intercession for him is accepted." In his narration, 'Ali bin Hujr said: "One hundred or more than that
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Ahmad Muhammad ShakirSahih
Al-AlbaniSahih
Bashar Awad MaaroufHasan Sahih
Zubair Ali ZaiSahih Muslim
In-book reference: 10:65