Hadith.2686 - He was asked about a person in the state of ihram sleeping on their face while on their mount.
Imam (as) said: "There is no harm in that."
Al-Kāfi #1253“I once asked abu ‘Abd Allah (a.s.), about a man who in the state of Ihram sleeps with a Zamilah (wrapping) on his face. He (the Imam) said,...