Sahih Bukhari, Chapter: Call to Prayers (Adhaan)

the mother of the faithful believers: Allah's Apostle in his last illness said, "Tell Abu Bakr to lead the people in the prayer." I said, "If Abu Bakr stood in your place, he would not be able to make the people hear him owing to his weeping. So please order 'Umar to lead the prayer." He said, "Tell Abu Bakr to lead the people in the prayer." I said to Hafsa, "Say to him, 'Abu Bakr is a softhearted man and if he stood in your place he would not be able to make the people hear him owing to his weeping. So order 'Umar to lead the people in the prayer.' " Hafsa did so but Allah's Apostle said, "Keep quiet. Verily you are the companions of (Prophet) Joseph. Tell Abu Bakr to lead the people in the prayer." Hafsa said to me, "I never got any good from you."