It is narrated from Sayyiduna Abu Umamah (may Allah be pleased with him): The Prophet (peace and blessings be upon him) passed by a man who was lying on his face, so he (peace and blessings be upon him) nudged him with his foot and said: "Get up, for this is the sleep of the people of Hell."
Hadith Referenceالمعجم الكبير للطبراني / باب الصاد / 7883