Musnad Ahmad 1153:26

Isma'il—meaning Ibn 'Ulayyah—narrated to us, Muhammad ibn al-Sa'ib narrated to us, from his mother, from 'Aishah, who said: When fever would seize the family of the Messenger of Allah (peace and blessings of Allah be upon him), he would order broth to be made. It would be made, then he would command them, and they would sip from it. Then he would say: "It—meaning—strengthens the heart of the sorrowful, and clears the heart of the sick, just as one of you clears dirt from her face with water."