Musnad Ahmed: Hadith 2190

The Messenger of Allah (ﷺ) was in the house of Maimoonah bint al-Harith and he got up to pray at night. [Ibn ‘Abbas said: So I stood on his left, and he took me by the hand and put me on his right, then he prayed, then he slept until he started to breathe deeply. Then Bilal came to him to give the call to prayer, and he got up and prayed without doing wudoo’. Hasan said - i.e., in his hadeeth: I was with the Prophet (ﷺ) in the house of Maimoonah, and when he finished praying he slept until he began to breathe deeply.