The Shaykh (Al-Mufid), may Allah سبحانه وتعالى support him, narrated to me, saying: Abu Al-Qasim Ja‘far bin Muhammad informed me, from Muhammad bin Ya‘qub, from a group of our companions, from Ahmad bin Muhammad, from Shadhan bin Al-Khalil Al-Naysaburi, from Ma‘mar bin ‘Umar, from Abu Ja‘far عليه السلام, who said: Imam عليه السلام said: "It is sufficient to wipe over the head the area of three fingers, and the same applies to the foot."