Musnad Ahmad 785:20

Rawh narrated to us, Zakariya narrated to us, Ibrahim ibn Maysarah narrated to us, that he heard ‘Amr ibn al-Sharid saying: It reached us that the Messenger of Allah (may Allah bless him and grant him peace) passed by a man while he was sleeping on his face, so he said: "This is the most hateful way of sleeping to Allah the Almighty."