Abu Dawud Book 2, Hadith Number 1288.
Chapter : Prayer in the forenoon.
Narated By ‘Aisha, wife of the Prophet (PBUH) : The Apostle of Allah (PBUH) never offered prayer in the forenoon, but I offered it. The Apostle of Allah (PBUH) would give up an action though he liked to do it, lest the people should continue it and it is prescribed for them.