The Prophet ﷺ passed by a man sleeping in the mosque on his stomach. He nudged him with his foot and said, "Get up and sit, for this is the sleeping posture of the people of Hell."
حدثنا يعقوب بن حميد بن كاسب حدثنا سلمة بن رجاء عن الوليد بن جميل الدمشقي أنه سمع القاسم بن عبد الرحمن يحدث
مر النبي ﷺ على رجل نائم في المسجد منبطح على وجهه فضربه برجله وقال قم واقعد فإنها نومة جهنمية
Graded hasan. Bukhari narrated it in Adab al-Mufrad, no. 1188, from the hadith of Walid bin Jameel, and he is truthful but makes mistakes (Taqrib), and the preceding hadith serves as a supporting witness for it.