Musnad Ahmad 1153:254

Yahya narrated to us, from Sufyan, Musa ibn Abi Aisha narrated to me, from Ubaydullah ibn Abdullah, from Aisha: We administered *ladud* (medicine poured into the side of the mouth) to the Messenger of Allah (ﷺ) during his illness, so he signaled: "Do not administer *ladud* to me." We said: "It is the dislike of a sick person for medicine." When he recovered, he said: "Did I not forbid you from administering *ladud* to me?" He said: "There shall not remain anyone among you but that they are administered *ladud*, except for al-Abbas, for he did not witness you."