Musnad Ahmad 25:358

Yunus and Hasan narrated to us, they said: Hammad ibn Salamah narrated to us, from ‘Amr ibn Dinar, from Kurayb ibn Abi Muslim, from Ibn ‘Abbas: "The Messenger of Allah (peace and blessings of Allah be upon him) was in the house of Maymunah bint al-Harith, and he stood to pray at night. He said: So I stood on his left, and he took my hand and placed me on his right. Then he prayed, then he slept until he snored. Then Bilal came to him with the Adhan, so he stood and prayed and did not perform ablution." Hasan said—meaning in his narration—: "I was with the Prophet (peace and blessings of Allah be upon him) in the house of Maymunah, and when he finished his prayer, he slept until he snored."