Jami` at-Tirmidhi Book 10, Hadith 52
"The Messenger of Allah came to Hamza on the Day of Uhud, he stood over him and saw that he had been mutilated. He said: Had it not been that Safiyyah would be distressed, then I would have left him to be eaten by the beasts until he was gathered on the Day of Judgment from their stomachs." He said: "Then he called for a Namirah to shroud him with. When it was extended over his head, it left his feet exposed, and when it was extended over his feet, it left his head exposed." He said: "There were many dead and few cloths." He said: "One, two and three men were shrouded in one cloth and buried in one grave." He said: "So the Messenger of Allah was asking which of them knew the most Quran, so he could put him toward the Qibalh." He said: "So the Messenger of Allah buried them and he did not perform (funeral prayers) for them."
The Prophet said: "Hurry up with the funeral (procession) for if it was good, you are advancing it to good, and if it was evil, then you are taking it off your necks."
"The Messenger of Allah would visit the sick, attend the funerals, ride a donkey, accept the invitation of a slave, and on the Day of Banu Quraizah he was on a donkey muzzled with a cord of fibers and a pack-saddle made of fibers."