The Shaykh (Al-Mufid), may Allah سبحانه وتعالى support him, informed me from Ahmad ibn Muhammad, from his father, from Saʿd ibn Abdullah, from Ahmad ibn Muhammad, from al-Husayn ibn Saʿid, from Ṣafwan, from Mansur ibn Hazim, who said: I asked Abu Abdullah عليه السلام about someone who forgot to wipe his head until he had already started the prayer. Imam عليه السلام said: "He should leave the prayer, wipe his head and his feet."