‘Abdallah b. ‘Amr reported God’s messenger as saying, “The supplication which gets the quickest answer is that made by one distant friend for another.”
I asked the Prophet’s permission to perform an ‘umra and he gave me permission, saying, “Include me in your supplication, little brother, and do not forget me.” Then he said a word to me for which I would not be willing to take the world in exchange.
Abu Dawud and Tirmidhi transmitted it, Tirmidhi’s version ending with “do not forget me.”