Ma'mar bin Rashid معمر بن راشد · The Book on Jana''iz (Funerals)

His father said: "I saw the Prophet, Abu Bakr, and Umar walking in front of the funeral."

"When the Messenger of Allah follows a corpse, he would not sit until (the deceased was) placed in the Lahd. A rabbi came upon him and said: 'This is what we do, O Muhammad'" He said: "So the Messenger of Allah sat, and he said: 'Differ from them.'"