I was with Mu'awiyah when his mu’adhdhin called the adhan, and Mu'awiya repeated the mu’adhdhin’s words, but when he said, “Come to prayer, he said, “There is no might and no power except in God,” and when he said, “Come to salvation,” he said, “There is no might and no power except in God the High, the Mighty.” After that he repeated the mu’adhdhin’s words, then said, “I heard God’s Messenger say that.”
Jabir said that he heard the Prophet say, “When the devil hears the summons to prayer he goes off till he is as far away as ar-Rauha’.” The transmitter said that ar-Rauha’ is thirty-six miles from Medina.
We were with God’s Messenger when Bilal got up and made the call to prayer. When he finished, God’s Messenger said, “If anyone says the same as this sincerely, he will enter paradise.”
‘Abdallah b. ‘Amr told of a man who said, “Messenger of God, the mu'adhdhins excel us.”* To him God’s Messenger replied, ‘Say the same words as they say, and when you come to the end, if you make any petition it will be granted to you.”
* This most probably means that they get a greater reward. The reply suggests how that may be counterbalanced.