Ibn ‘Umar said that in the time of God's Messenger the phrases in the adhan were uttered twice each and in the iqama once each, except for saying, ‘‘The time for prayer has come. The time for prayer has come.”
When I asked God’s Messenger to teach me the sunna relating to the adhan he wiped the forepart of his head and said: You must say, “God is most great. God is most great. God is most great. God is most great,” raising your voice while saying these words. Then you must say, “I testify that there is no god but God. I testify that there is no god but God. I testify that Muhammad is God’s Messenger. I testify that Muhammad is God’s Messenger,” lowering your voice while saying these words. Then you must raise your voice in making the testimony, “I testify that there is no god but God. I testify that there is no god but God. I testify that Muhammad is God’s Messenger. I testify that Muhammad is God’s Messenger. Come to prayer. Come to prayer. Come to salvation. Come to salvation”; and if it is the Morning Prayer you must say, “Prayer is better than sleep. Prayer is better than sleep. God’s is most great. God is most great. There is no god but God.”
Abu Mahdhura said that God's Messenger himself taught him how to make the call to prayer, telling him to say, “God is most great. God is most great. God is most great. God is most great. I testify that there is no god but God. I testify that there is no god but God. I testify that Muhammad is God’s Messenger. I testify that Muhammad is God’s Messenger”; then to repeat, “I testify that there is no god but God. I testify that there is no god but God. I testify that Muhammad is God’s Messenger. I testify that Muhammad is God’s Messenger. Come to prayer. Come to prayer. Come to salvation. Come to salvation. God is most great. God is most great. There is no god but God.”