Musnad Abu Ya'la al-Mawsili 150:278

'Abbad ibn Musa narrated to us, Ibn al-Mubarak narrated to us, Yunus informed me, from al-Zuhri, from Abu Salamah, from 'Aishah: That the Messenger of Allah (may Allah bless him and grant him peace), when he wanted to sleep while he was in a state of major ritual impurity (junub), he would perform ablution like his ablution for prayer. And when he wanted to eat, he would wash his hands, then he would eat.