Sunan Ibn Majah, Chapter: Chapters Regarding Funerals

"When the Messenger of Allah (saw) passed away, Abu Bakr was with his wife, the daughter of Kharijah, in villages surrounding Al-Madinah. They started to say: 'The Prophet (saw) has not died, rather he has been overcome with what used to overcome him at the time of Revelation.' Then Abu Bakr came and uncovered his (the Prophet's (saw)) face, kissed him between the eyes and said: 'You are too noble before Allah for Him to cause you to die twice. By Allah, the Messenger of Allah (saw) has indeed died.' Umar was in a corner of the mosque saying: 'By Allah, the Messenger of Allah (saw) has not died and he will never die until the hands and feet of most of the hypocrites are cut off.' Then Abu Bakr stood up, ascended the pulpit and said: 'Whoever used to worship Allah, Allah is alive and will never die. Whoever used to worship Muhammad, Muhammad is dead. "Muhammad is no more than a Messenger, and indeed (many) Messengers have passed away before him. If he dies or is killed, will you then turn back on your heels (as disbelievers)? And he who turns back on his heels, not the least harm will he do to Allah; and Allah will give reward to those who are grateful.'" [3:144] Umar said: 'It was as if I had never read (that Verse) before that day.'" Sahih