Muhammad ibn Yaqub from Ahmad ibn Idris from Muhammad ibn Ahmad ibn Yahya from Ahmad ibn al-Hasan ibn Ali from Amr ibn Said from Musaddiq ibn Sadaqah from Ammar al-Sabati from Abu Abdillah عليه السلام: I asked Imam al-Sadiq عليه السلام about a man who leads a group in prayer while they are in a place lower than the place where he is praying. Imam عليه السلام said: “If the imam (of prayer) is on something like a platform (dukkan) or on a spot higher than their spot, their prayer is not valid.” (al-Sabbati asked) “But if he is higher than them by the measure of a finger, or whether it is more or less, if the elevation is by the measure of a span (shibr), then if it is flat ground and there happens to be an elevated spot from which the imam (of prayer) stands and those behind him stand below him, and the ground is flat except that they are in a sloped area” Imam عليه السلام said: “There is no harm.” Imam عليه السلام was also asked: “And if the imam (of prayer) is in a position lower than that of those praying behind him?” Imam عليه السلام said: “There is no harm.” And Imam عليه السلام said: “And if a man is on top of a roof or anything similar a platform or something else and the imam (of prayer) is praying on the ground below him, it is permissible for the man to pray behind him and follow his prayer, even if he is significantly higher than him.”