Jami` at-Tirmidhi 1046
جامع الترمذي#1046SahihIbn Umar narrated:"When he Prophet put the deceased in the grave" He said: And Abu Khalid (one of the narrators) said [one time]: "When he placed the deceased in the Lahd" - "He said one time: 'In the Name of Allah, by His command and upon the Millah of the Messenger of Allah.' and one time he said: 'In the Name of Allah, by His command and upon the Sunnah of the Messenger of 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
Zubair Ali ZaiSahih
In-book reference: 10:82