Abu Dawud Book 1, Hadith Number 366.

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

Narated By Umm Habibah : Mu’awiyah ibn AbuSufyan asked his sister Umm Habibah, the wife of the Prophet (PBUH): Would the apostle of Allah (PBUH) pray in the clothe in which he had an intercourse? She said: Yes, when he would not see any impurity in it.