Musnad Ahmad 1153:1117

Hushaym narrated to us, from Isma'il ibn Abi Khalid, from Abu Ishaq, from al-Aswad, from 'Aishah, who said: "The Messenger of Allah (peace and blessings of Allah be upon him) would sleep while he was in a state of major ritual impurity (junub), and he would not touch water."