Response From the Heart to Enter Paradise.

The prophet (peace be upon him) said: “When the Mu’adhdhin (who Calls the faithful to prayer)  says: Allah is the Greatest, Allah is the Greatest, and one of you should make this response: Allah is the Greatest, Allah is the Greatest; (and when the Mu’adhdhin) says: I testify that there is no god but Allah, one should respond: I testify that there is no god but Allah, and when he says: I testify that Muhammad is the Messenger of Allah, one should make a response: I testify that Muhammad is Allah’s Messenger.When he (the Mu’adhdhin) says: Come to prayer, one should make a response: There is no might and no power except with Allah.When he (the Mu’adhdhin) says: Come to salvation, one should respond: There is no might and no power except with Allah, and when he (the Mu’adhdhin) says: Allah is the Greatest, Allah is the Greatest, then make a response: Allah is the Greatest, Allah is the Greatest. When he (the Mu’adhdhin) says: There is no god but Allah, and he who makes a response from the heart: There is no god but Allah, he will enter Paradise.” [Abu-Dawood]