Abu Dawud Book 1, Hadith Number 218.
Chapter : A person with sexual defilement may repeat intercourse without taking a bath.
Narated By Anas : One day the Apostle of Allah (may peace be upon him) had sexual intercourse with (all) his wives with a single bath.
Abu Dawud said: This tradition has been transmitted through another chain of narrators.
Abu Dawud said: The tradition narrated by Anas is more sound than this tradition.