What is the ruling on covering the forehead during prostration with a skullcap (ṭāqiyyah) or head covering (ghutrah), which prevents the forehead from touching the mosque carpet?

The scholars are unanimous that the preferred action is for the forehead to directly touch the ground during prostration. However, if the worshipper prostrates on his turban or ghutra (head covering), his prostration is valid according to most scholars, based on the hadith of Anas: "We used to pray with the Messenger of Allah, peace and blessings be upon him, in intense heat. If one of us was unable to enable his forehead to the ground, he would spread his garment and prostrate on it."

The Shafi'is, however, hold that it is obligatory to uncover the part of the forehead that is considered part of the forehead and for it to directly touch the place of prostration. If one prostrates on his turban or the edge of his sleeve or the edge of his turban, and these move with his movement, his prayer is invalid. However, if he prostrates on something detached from him, his prayer is valid. The more cautious approach is to uncover the forehead and have it directly touch the place of prostration.