Musnad Abu Ya'la al-Mawsili 3:24

Abu Khaythama narrated to us, Abd al-Rahman narrated to us, from Shu'bah, from 'Amr ibn Murrah, from 'Abd Allah ibn Salamah, from 'Ali: The Messenger of Allah (may Allah bless him and grant him peace) passed by me while I was complaining [of pain], and I was saying: "O Allah, if my appointed time has arrived, then grant me rest; and if it is delayed, then raise me; and if it is a trial, then grant me patience." He struck my chest with his hand and said: "O Allah, grant him wellness and heal him." I did not complain of that pain of mine after that.