Musnad Ahmad 1153:855

Ali ibn Ishaq narrated to us, he said: Abdullah informed us, he said: Yunus informed us, from al-Zuhri, he said: Abu Salamah ibn Abd al-Rahman narrated to me, that Aisha, the wife of the Prophet, may Allah bless him and grant him peace, said: "When the Messenger of Allah, may Allah bless him and grant him peace, intended to sleep while he was in a state of major ritual impurity (junub), he would perform his ablution for prayer. And when he intended to eat or drink, she said: He would wash his hands, then eat and drink."