Bukhari Collection: ::Book Number 9:: Hadith # 35
Narrated `Aisha:We poured medicine into the mouth of Allah's Apostle during his illness, and he pointed out to us intending to say, "Don't pour medicine into my mouth." We thought that his refusal was out of the aversion a patient usually has for medicine. When he improved and felt a bit better he said (to us.) "Didn't I forbid you to pour medicine into my mouth?" We said, "We thought (you did so) because of the aversion, one usually have for medicine." Allah's Apostle said, "There is none of you but will be forced to drink medicine, and I will watch you, except Al-`Abbas, for he did not witness this act of yours."