The Book of Prayers (Kitab Al-Salat)
Muslim :: Book 4 : Hadith 835
'A'isha, the wife of the Apostle of Allah (may peace be upon him), said: I tried to dissuade the Messenger of Allah (may peace be upon him) 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 (may peace be upon him) should leave Abu Bakr aside in this matter.