Chapter on the Prayer Times (Mawaqit)

From him, from Musa ibn Al-Hasan, from Ahmad ibn Hilal, from Muhammad ibn Abi Umayr, from Ja'far ibn Uthman, from Sama'ah ibn Mehran who said: I said to Abu Abdillah عليه السلام, peace be upon him, regarding Maghrib: “Sometimes we pray while we fear that the sun might still be behind the mountain or that the mountain has hidden it from us.” Imam عليه السلام said: "You are not required to climb the mountain."