Hadith.840 - Ammar al-Sabati narrate from Imam Jafar ibn Muhammad Al-Sadiq عليه السلام that He said:
"The area between the hairline and the tip of the nose is considered a place of prostration (masjid), so whatever part of it touches the ground suffices."
And Zurarah also narrated a similar statement from Imam عليه السلام.
