Musnad Ahmad 1153:1645

Yahya narrated to us, from Hisham, who said: My father informed me, from Aisha, who said: The Prophet (peace and blessings of Allah be upon him) said during his illness in which he died: "Command Abu Bakr to lead the people in prayer." I said: "If Abu Bakr stands in your place, the people will not hear him because of his weeping." He said: "Command Abu Bakr." I said to Hafsa: "Say that Abu Bakr will not make the people hear because of his weeping, so if you were to command Umar..." He said: "You are the companions of Yusuf. Command Abu Bakr to lead the people in prayer." Hafsa turned to me and said: "I was not to attain any good from you."