Jami` at-Tirmidhi 536

جامع الترمذي#536Sahih

Kathir bin Abdullah narrated from this father, from his grandfather:"The Prophet said the Takbir in the first (Rak'ah) sever (times) before the recitation, and in the last, five (times) before the recitation

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

Zubair Ali ZaiHasan

In-book reference: 5:7

All of Jami` at-Tirmidhi