Narrated Jabir reported God’s Messenger as saying:
If anyone says when he hears the summons, “O God, Lord of this perfect call and of the prayer which is established for all time, grant Muhammad the wasila and excellency, and raise him up in a praiseworthy position (Al-Qur’an; 17:79) which Thou hast promised,” he will be assured of my intercession.
Narrated ‘Umar reported God’s Messenger as saying:
When the mu’adhdhin says, “God is most great, God is most great,” and one of you makes the response, “God is most great, God is most great”; then says, “I testify that there is no god but God,” and he makes the response, “I testify that there is no god but God”; then says, “I testify that Muhammad is God’s Messenger,” and he makes the response, “I testify that Muhammad is God’s Messenger”; then says, “Come to prayer,” and he makes the response, “There is no might and no power except in God”; then says, “Come to salvation,” and he makes the response, “There is no might and no power except in God”; then says, “God is most great, God is most great,” and he makes the response, “God is most great, God is most great”; then says, “There is no god but God,” and he makes the response, “There is no god but God”; if he says this from his heart, he will enter paradise.
Anas said that the Prophet used to attack the enemy at dawn, and he would sometimes hear the adhan, so if he heard an adhan he stopped, but otherwise he attacked. Once on hearing a man say, “God is most great, God is most great,” God’s Messenger said, “You follow Islam.” Then hearing him say, “There is no god but God,” he said, “You have come forth from hell.” They looked at him and found that he was a goatherd.
‘Abdallah b. ‘Amr b. al-‘As reported God's Messenger as saying, “When you hear the mu’adhdhin repeat what he says, then invoke a blessing on me, for everyone who invokes one blessing on me will receive ten blessings from God. Then ask God to give me the wasila, which is a rank in paradise fitting for only one of God’s servants, and I hope that I may be the one. If anyone asks that I be given the wasila, he will be assured of my intercession.”