Reference : Hisn al-Muslim 163

بِسْـمِ اللهِ 
وَعَلـى سُـنَّةِ رَسـولِ الله
Bismillāh
wa `alā sunnati Rasūlillāh.


With the Name of Allah, 
and according to the Sunnah of the Messenger of Allah.

Reference:
Abu Dawud 3/314 with an authentic chain. Ahmad also recorded it with the 
wording: With the Name of Allah, and according to the religion of the 
Messenger of Allah. Its chain is also authentic.

Chapter: Placing the deceased in the grave