Ahmad ibn Muhammad, from Muhammad ibn Isma’il, from Abu Isma’il Al-Sarraj, from Abdullah ibn Uthman, from Qudamah ibn Abi Zayd Al-Himar, from some of our companions, narrated from Abu Abdullah عليه السلام: I asked Imam عليه السلام: "What is the minimum distance between a water well and a drain?" Imam عليه السلام said: "If it is flat land, then seven cubits. If it is rocky (mountainous) land, then five cubits." Then Imam عليه السلام said: "Water should flow toward the Qiblah to the right, and it should flow from the right of the Qiblah to the left of the Qiblah, and from the left of the Qiblah to the right of the Qiblah. However, it should not flow from the Qiblah to the direction opposite to the Qiblah."