Musnad Ahmad 32:360

Safwan ibn Isa and Zayd ibn al-Hubab narrated to us, saying: Usama ibn Zayd informed us, from al-Zuhri, from Anas ibn Malik, that the Messenger of Allah (ﷺ) came upon Hamza and stood over him, and he saw that he had been mutilated. He said: "Were it not that Safiyya would find something in herself [i.e., be deeply grieved], I would have left him until the beasts of prey ate him"—Zayd ibn al-Hubab said: "until the vermin ate him"—"so that he would be resurrected from their bellies." Then he said: He called for a *nimra* (a striped garment) and shrouded him in it. He said: When it was pulled over his head, his feet were exposed, and when it was pulled over his feet, his head was exposed. He said: The number of the slain was great, and the garments were few. He said: So he would shroud one man, or two men—Safwan was uncertain—or three in a single garment. He said: The Messenger of Allah (ﷺ) would ask which of them had memorized the most Quran, and he would place him forward toward the *qibla*. He said: The Messenger of Allah (ﷺ) buried them and did not perform the funeral prayer over them. Zayd ibn al-Hubab said: So one man, two men, and three men would be shrouded in a single garment.