The Messenger of Allah (ﷺ) said: When the Imam says:" Allah listens to him who praises Him." you should say:" O Allah, our Lord for You is the praise." for if what anyone says synchronises with what the angels say, his past sins will be forgiven.
Reference: Sahih Muslim 409 a In-book : Book 4, Hadith 75 USC-MSA web (English) : Book 4, Hadith 809 (deprecated)
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