#68 Yahya bin Hassan informed us, Hammad bin Salamah narrated to us, from Suhayl bin Abi Salih, from his father, from Abu Hurairah (may Allah be pleased with him), that the Messenger of Allah (pbuh) said: "If one of you feels a movement in his posterior while in prayer, and he is uncertain whether he has invalidated his ritual purity or not, he should not depart from the prayer until he hears a sound or perceives an odor."