Sahih Muslim Book 4, Hadith Number 840.

Anas b. Malik reported, Abu Bakr led them in prayer due to the illness of the Messenger of Allah (may peace be upon him) of which he died. It was a Monday and they stood in rows for prayer. The Messenger of Allah (may peace be upon him) drew aside the curtain of (‘Aisha’s) apartment and looked at us while he was standing, and his (Prophet’s) face was (as bright) as the paper of the Holy Book. The Messenger of Allah (may peace be upon him) felt happy and smiled. And we were confounded with joy while in prayer due to the arrival (among our midst) of the Messenger of Allah (may peace be upon him), Abu Bakr stepped back upon his heels to say prayer in a row perceiving that the Messenger of Allah (may peace be upon him) had come out for prayer. The Messenger of Allah (may peace be upon him) with the help of his hand signed to them to complete their prayer. The Messenger of Allah (may peace be upon him) went back (to his apartment) and drew the curtain. He (the narrator) said: The Messenger of Allah (may peace be upon him) breathed his last on that very day.