It was narrated that 'Aishah said:
"The Messenger of Allah used to divide his time equally among his wives, then he would say 'O Allah, this is what I am doing with regard to that which is within my control, so do not hold me accountable for that which is under Your control and is beyond my control.'"
English reference: Vol. 3, Book 9, Hadith 1971
Arabic reference: Book 9, Hadith 2047