Sahih Muslim Book 4, Hadith 101
I tried to dissuade the Messenger of Allah (ﷺ) from it (i. e. from appointing Abu Bakr as the Imam.) and my insistence upon it was not due to the fact that I entertained any apprehension in my mind that the people would not love the man who would occupy his (Prophet's) place (i. e. who would be appointed as his caliph) and I feared that the people would be superstitious about one who would occupy his place. I, therefore, desired that the Messenger of Allah (ﷺ) should leave Abu Bakr aside in this matter.
When the Messenger of Allah (ﷺ) fell ill and his illness became serious, he asked permission from his wives to stay in my house during his illness. They gave him permission to do so. He stepped out (of'A'isha's apartment for prayer) supported by two persons. (He was so much weak) that his feet dragged on the ground and he was being supported by 'Abbas b. 'Abd al-Muttalib and another person. 'Ubaidullah said: I informed 'Abdullah (b. 'Abbas) about that which 'A'isha had said. 'Abdullah b. 'Abbas said: Do you know the man whose name 'A'isha did not mention? He said: No. Ibn 'Abbas said: It was 'Ali.
When the Messenger of Allah (ﷺ) came to my house, he said: Ask Abu Bakr to lead people in prayer. 'A'isha narrated: I said, Messenger of Allah, Abu Bakr is a man of tenderly feelings; as he recites the Qur'an, he cannot help shedding tears: so better command anyone else to lead the prayer. By Allah, there is nothing disturbing in it for me but the idea that the people may not takeevil omen with regard to one who is the first to occupy the place of the Messenger of Allah (ﷺ). I tried to dissuade him (the Holy Prophet) twice or thrice (from appointing my father as an Imam in prayer), but he ordered Abu Bakr to lead the people in prayer and said: You women are like those (who had) surrounded Yusuf.