BELIEVE in God and His Apostle, and spend on others out of that of which He has made you trustees: or, those of you who have attained to faith and who spend freely [in God’s cause] shall have a great reward.
Al-Hadid (Iron) Verse 7
Allah's Apostle said, "Whenever you hear the Adhan, say what the Mu'adhdhin is saying.
Sahih Bukhari: Volume 1, Book 11, Number 585