Narrated Abu Huraira reported God’s Messenger as saying:
When the imam says, “God listens to him who praises Him," say, “O God, our Lord, to Thee be the praise for if what anyone says synchronises with what the angels say, he will be forgiven his past sins.
Ibn ‘Abbas reported God’s Messenger as saying, “I have been prohibited to recite the Qur’an when bowing or prostrating myself; so when bowing magnify the Lord, and when prostrating yourselves be earnest in supplication, for it is fitting that your supplications should be answered.’’
‘Abdallah b. Abu Aufa said that when God’s Messenger raised his back after bowing he said, “God listens to him who praises Him. O God, our Lord, to Thee be the praise in all the heavens and all the earth, and all that it pleases Thee to create afterwards.”
