Abu Dawud Book 1, Hadith Number 250.

Chapter : A person who is sexually defiled is permitted to eat anything before washing.

Narated By ‘Aisha, Ummul Mu’minin : The Apostle of Allah (PBUH) took a bath and offered two rak’ahs of prayer and said the dawn prayer. I do not think he performed ablution afresh after taking a bath.