What my teacher (Shaykh Al-Mufid) narrated to me, may Allah سبحانه وتعالى support him, from Ahmad ibn Muhammad, from his father, from Ahmad ibn Idris and Sa’d ibn Abdullah, from Ahmad ibn Muhammad, from al-Husayn ibn Sa’id, from Hammad, and from Muhammad ibn Ya’qub, from Ali ibn Ibrahim, from his father, and from Muhammad ibn Isma’il, from al-Fadl ibn Shadhan, all from Hammad, from Hariz, from Zurarah, from Abu Ja’far عليه السلام, who said: Hammad said, (that) Hariz said, (that) Zurarah said:
Imam عليه السلام said: "If you are seated performing your ablution and do not know whether you have washed your forearms or not, then repeat washing them and everything you doubt whether you have washed or wiped among what Allah سبحانه وتعالى has mentioned, as long as you are still in the state of ablution. However, if you have finished the ablution, left that state, and entered another state, such as prayer or something else, and then doubt any part of what Allah سبحانه وتعالى has mentioned as obligatory in ablution, there is nothing upon you regarding it. If you doubt wiping your head and find moisture in your beard, then wipe your head and the tops of your feet with it. If you do not find any moisture, do not invalidate your ablution due to doubt and proceed with your prayer. If you are certain that you did not complete your ablution, then repeat what you left out with certainty until you complete the ablution." I (Zurarah) asked Imam عليه السلام: "What about a man who leaves part of his forearm or part of his body unwashed in the ritual bath (ghusl)?" Imam عليه السلام replied, "If he doubts and there is moisture on his body while he is in prayer, let him wipe over it. If he is certain, let him return and wash the missed part, as long as he has not lost the moisture. If doubt arises after he has entered the prayer, let him continue his prayer, and there is nothing upon him. If he becomes certain, let him return and wash the missed part. If he sees the missed area with moisture, let him wipe it and repeat the prayer out of certainty. If he is in doubt, there is nothing upon him for his doubt; let him continue with his prayer."
