(18) باب التَّسْمِيعِ وَالتَّحْمِيدِ وَالتَّأْمِينِ
Abu Huraira reported:
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 Thee 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 reference: Book 4, Hadith 75
USC-MSA web (English) reference(deprecated numbering scheme): Book 4, Hadith 809