Jami` at-Tirmidhi 976
جامع الترمذي#976SahihAbu Sa'eed Al-Khudri narrated that:The Prophet said: "Instruct your dying to say: (La illaha illallah) 'None has the right to be worshipped but Allah
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: 10:12