When the Prophet ﷺ placed the deceased in the grave, he would say, "In the name of Allah and upon the way of the Messenger of Allah ﷺ." This is the wording of Muslim.
حدثنا محمد بن كثير ح و حدثنا مسلم بن إبراهيم حدثنا همام عن قتادة عن أبي الصديق
أن النبي ﷺ كان إذا وضع الميت في القبر قال بسم الله وعلى سنة رسول الله ﷺ هذا لفظ مسلم
[Sahih] Ahmad narrated it (2/27), and Nasai in Amal al-Yawm wal-Layla (no. 1088), from the hadith of Hammam, with this wording. Ibn Jarud graded it sahih (no. 548), as did Ibn Hibban (no. 773), and Hakim according to the standard of the two Shaykhs (1/366), and Dhahabi concurred with him. The hadith has corroborating narrations, and with them it is sahih.