6. Ahmad ibn Muhammad from through the chain of his narrators has said the following: “Abu ‘Abd Allah (a.s.), was asked about the case of one on whose forehead there is something because of which he is not able to perform Sajdah (prostration) on it. He (the Imam) said, ‘He places his chin on the ground; Allah, most Majestic, most Glorious, has said, “They fall down on their chins prostrating.’”” (17:107)