Sunan Ibn Majah
3724
Sahih+2

It was narrated that Abu Dharr said:"The Prophet(ﷺ) passed by me and I was lying on my stomach. He nudged me with his foot and said: 'O Junaidib! This is how the people of Hell lie

SahihAl-Albani
SahihMuhammad Fouad Abd al-Baqi