Abu Dawud
Purification (Kitab Al-Taharah)
Book Number: 001 / Hadith Number: 226
Narated By 'Aisha, Ummul Mu'minin : Ghudayf ibn al-Harith reported: I asked 'Aisha: Have you seen the Apostle of Allah (pbuh) washing (because of defilement) at the beginning of the night or at the end?
She replied: Sometimes he would take a bath at the beginning of the night and sometimes at the end.
Thereupon I exclaimed: Allah is most Great. All Praise be to Allah Who made this matter accommodative.
I again asked her: What do you think, did the Apostle of Allah (pbuh) say the witr prayer (additional prayer after obligatory prayer at night) in the beginning of the night or at the end?
She replied: Sometimes he would say the witr prayer at the beginning of the night and sometimes at the end.
I exclaimed: Allah is most Great. All praise be to Allah Who made the matter accommodative.
Again I asked her: What do you think, did the Apostle of Allah (pbuh) recite the Qur'an (in the prayer) loudly or softly?
She replied: Sometimes he would recite loudly and sometimes softly.
I exclaimed: Allah is most Great. All praise be to Allah Who made the matter flexible.