16. Ali ibn Ibrahim has narrated from Muhammad ibn ‘Isa from Yunus from Zur’ah, from Sama‘ah who has said the following: “Abu ‘Abd Allah عليه السلام, has said, ‘After using toilet if you forget to wash clean your buttocks (because of feces) and take Wudu’, then remember after performing Salah (prayer), you must perform your Salah (prayer) again. If you wash your buttocks clean but forget washing your urethra clean and perform Salah (prayer), you must take Wudu’, wash your urethra and perform your Salah (prayer) again. It is because urine is not like feces.’”