Musnad Ahmad 5:278

Muhammad ibn Ja‘far narrated to us, Shu‘bah narrated to us, from ‘Amr ibn Murrah, from ‘Abdullah ibn Salamah, from ‘Ali ibn Abi Talib, who said: I was complaining of an ailment, and the Messenger of Allah (peace and blessings of Allah be upon him) passed by me while I was saying: "O Allah, if my appointed time has arrived, then grant me rest; and if it is delayed, then raise me up; and if it is a trial, then grant me patience." The Messenger of Allah (peace and blessings of Allah be upon him) said: "What did you say?" So he repeated to him what he had said. He said: So he struck him with his foot and said: "O Allah, grant him wellness," or "O Allah, heal him" — Shu‘bah was in doubt. He said: So I did not complain of that pain of mine after that.