Musnad Abu Ya'la al-Mawsili 150:203

Dāwūd ibn Rashīd narrated to us, Abū Ḥafṣ al-Abbār narrated to us, from Manṣūr, from Mujāhid, from ‘Ā’ishah, who said: The Messenger of Allah (ﷺ) would wake up in the morning while he was in a state of ritual impurity (junub), and he would complete his fast.