سنن أبي داود

‘Umar b. al-khattab reported the Messenger of Allah (May peace be upon him) as saying; When the MU’ADHDHIN says: “Allah is most great, Allah is most great”, and one of you says in response: “Allah is most great”, Allah is most great; then says: “ I testify tht there is no god but Allah”, and he says in response: “I testify that there is no god but Allah”, then say:” I testify that Muhammad is the Messenger of Allah”, and he makes the response: “ I testify that Muhammad is the Messenger of Allah”, then says: “Come to prayer”, and he makes the response: “There is no might and no power except in Allah”: then says: “ Allah is most great, Allah is most great”, and he makes the response: “Allah is most great”, then says: “There is no god but Allah”, if he says this from his heart, he enter Paradise.