Musnad Abu Ya'la al-Mawsili 152:217

Abu Khaythama narrated to us, Abd al-Rahman narrated to us, al-Mas'udi narrated to us, from Jami' ibn Shaddad, from Abd al-Rahman ibn Abi 'Alqama, from Abdullah, who said: When the Messenger of Allah (may Allah bless him and grant him peace) returned from al-Hudaybiyah, he stopped at a place and camped there for the night. He said, "Who will keep watch for us?" Abdullah said: I said, "I will." The Messenger of Allah (may Allah bless him and grant him peace) said, "You will sleep." He said that two or three times. Then he said, "You, then." So I kept watch for them until, when it was the break of dawn, what the Messenger of Allah (may Allah bless him and grant him peace) had said overcame me, and I did not wake up until the heat of the sun was upon our backs. The Messenger of Allah (may Allah bless him and grant him peace) stood up and did as he used to do, then he prayed the morning prayer. Then he said, "If Allah had willed, you would not have slept through it, but it is for those who come after you; so it is for whoever sleeps or forgets."