Musnad Abu Ya'la al-Mawsili 149:122

Ibrahim narrated to us, Hammad narrated to us, from Hisham ibn Urwah, from his father, from Aisha, that the Messenger of Allah (may Allah bless him and grant him peace) said during his illness: "Let Abu Bakr lead the people in prayer." Aisha said to Hafsa: "Tell him that Abu Bakr is a man of tender heart, and if he stands in your place, the people will not hear him because of his weeping. So command Umar to lead the people in prayer." Hafsa said that to the Prophet (may Allah bless him and grant him peace), and he said: "Let Abu Bakr lead the people in prayer." Aisha said to Hafsa the same as her first statement, and he said: "Let Abu Bakr lead the people in prayer." Aisha repeated to Hafsa the same statement for the Prophet (may Allah bless him and grant him peace), and he said: "Leave me alone, for you are indeed the companions of Yusuf. Let Abu Bakr lead the people in prayer."