Abu Huraira reported God’s messenger as saying, “Every prophet has a supplication which receives an answer, but whereas every prophet made his supplication in this world, I have kept mine till the day of resurrection to be used in intercession for my people, and if God will, it will reach those of my people who have died without associating anything with God.”
Muslim transmitted it, and Bukhari has a shorter version.
He reported God’s messenger as. saying, “O God, I have entered into a covenant with Thee which Thou wilt not break. I am only a human being, so when I have injured, reviled, cursed or beaten a believer, make that for him a mercy, a purification and a means by which Thou wilt bring him near to Thee on the day of resurrection.”
(Bukhari and Muslim.)
He reported God's messenger as saying, “When one of you makes supplication he must not say, ‘O God, forgive me if Thou wilt, show mercy to me if Thou wilt, provide for me if Thou wilt’, but must make his request definite, for He does what He wills and there is no one to impose compulsion on Him.”
Bukhari transmitted it.
He reported God’s messenger as saying, “When one of you makes supplication he must not say, ‘O God, forgive me if Thou wilt, but must be definite and cherish a great desire, for nothing which God gives is burdensome to Him.”
Muslim transmitted it.
He reported God’s messenger as saying, “A servant is granted an answer provided he does not ask for anything sinful or for breaking ties of relationship, and provided he does not demand an answer quickly.” On being asked what demanding an answer quickly meant, God’s messenger replied, “It is when he says he has prayed and prayed and does not think he will be answered, so he grows weary in such circumstances and gives up supplication.”
Muslim transmitted it.
Abu Darda’ reported God’s messenger as saying, “A Muslim’s supplication for an absent brother receives an answer. An angel is stationed at his head, and as often as he makes supplication that his brother may be given what is good the angel who is put in charge of him says, ‘Amen, and may you receive the like’.”
Muslim transmitted it.
Jabir reported God’s messenger as saying, “Do not invoke curses on yourselves, or on your children, or on your possessions lest you happen to do it at a time when God is asked for something and grants your requests.”
Muslim transmitted it.
An-Nu‘man b. Bashir reported God’s messenger as saying, “Supplication is worship.” He then recited, “And your Lord said, If you call on me I will aswer you.”*
*Qur’an, xl, 60.
Ahmad, Tirmidhi, Abu Dawud, Nasa'i and Ibn Majah transmitted it.
Abu Huraira reported God’s messenger as saying, “Nothing is more honourable in God’s sight than supplication.”
Tirmidhi and Ibn Majah transmitted it, Tirmidhi saying this is a hasan gharib tradition.
Salman al-Farisi reported God’s messenger as saying, “Nothing but supplication averts the decree, and nothing but righteousness increases life.”
Tirmidhi transmitted it.
Ibn ‘Umar reported God’s messenger as saying, "Supplication is beneficial regarding things which have happened and things which have not happened, so devote yourselves to supplication, servants of God."
Tirmidhi transmitted it, and Ahmad transmitted it from Mu'adh b. Jabal. Tirmidhi said this is a gharib tradition.
Jabir reported God’s messenger as saying, “No one offers a supplication without God bringing him what he asks or keeping away from him a like amount of evil, provided he does not ask for something sinful or for breaking ties of relationship.”
Tirmidhi transmitted it.
Ibn Mas'ud reported God’s messenger as saying, “Ask God for some of His bounty, for God likes to be asked, and the most excellent worship is expectation of relief.”
Tirmidhi transmitted it, saying this is a gharib tradition.
Ibn ‘Umar reported God's messenger as saying, “If the gate of supplication is opened for any of you, the gates of mercy will be opened for him, and God is not asked for anything He likes so much as to be asked for security.”
Tirmidhi transmitted it.
Abu Huraira reported God’s messenger as saying, “If anyone finds pleasure in receiving an answer from God in times of difficulty, he should make many supplications when times are easy.”
Tirmidhi transmitted it, saying this is a gharib tradition.
He reported God’s messenger as saying, “Supplicate God when you are assured of being answered, and know that God does not answer a supplication which comes from a careless and inattentive heart.”
Tirmidhi transmitted it, saying this is a gharib tradition.
Malik b. Yasar reported God’s messenger as saying, “When you make requests of God, do so with the palms of your hands and not the backs upward.” In the version of Ibn ‘Abbas he said, “When you make requests of God, do so with the palms of your hands and not the backs upward, and when you are finished wipe your faces with them.”
Abu Dawud transmitted it.
Salman reported God’s messenger as saying, “Your Lord is munificent and generous, and is ashamed to turn away empty the hands of a servant when he raises them to Him .”
Tirmidhi, Abu Dawud and Baihaqi, in [Kitab] ad-Da'awat al-kabir, transmitted it.