Narrated Abu Huraira reported God’s messenger as saying, “There are three whose supplication is not rejected:
one who has just ended a fast, a just imam, and one who has been wronged whose supplication is raised by God above the clouds and for which the gates of heaven are opened. The Lord says, ‘I swear by my might that I will certainly help you, though it be after some time’.”
Anas reported God's messenger as saying, “Let one of you ask his Lord for all that he needs, even for the thong of his sandal when it is cut.” He added in a version from Thabit al-Bunani in mursal form, “even asking Him for salt, and even asking Him for his thong when it is cut.”
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.”