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.  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ إِذَا قَالَ الإِمَامُ سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ فَقُولُوا اللَّهُمَّ رَبَّنَا لَكَ الْحَمْدُ فَإِنَّهُ مَنْ وَافَقَ قَوْلُهُ قَوْلَ الْمَلاَئِكَةِ غُفِرَ لَهُ مَا تَقَدَّمَ مِنْ ذَنْبِهِ  

A hadith like this is narrated by Abu Huraira by another chain of transmitters.  

عَنِ النَّبِيِّ ﷺ بِمَعْنَى حَدِيثِ سُمَىٍّ  

The Messenger of Allah ﷺ said: SayAmin when the Imam says Amin, for it anyone's utterance of Amin synchronises with that of the angels, he will be forgiven his past sins.  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ إِذَا أَمَّنَ الإِمَامُ فَأَمِّنُوا فَإِنَّهُ مَنْ وَافَقَ تَأْمِينُهُ تَأْمِينَ الْمَلاَئِكَةِ غُفِرَ لَهُ مَا تَقَدَّمَ مِنْ ذَنْبِهِ قَالَ ابْنُ شِهَابٍ كَانَ رَسُولُ اللَّهِ ﷺ يَقُولُ آمِينَ  

I heard from the Messenger of Allah ﷺ the hadith like one transmitted by Malik, but he made no mention of the words of Shihab.  

سَمِعْتُ رَسُولَ اللَّهِ ﷺ بِمِثْلِ حَدِيثِ مَالِكٍ وَلَمْ يَذْكُرْ قَوْلَ ابْنِ شِهَابٍ  

The Messenger of Allah ﷺ said: When anyone amongst you utters Amin in prayer and the angels in the sky also utter Amin, and this (utterance of the one) synchronises with (that of) the other, all his previous sins are pardoned.  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ إِذَا قَالَ أَحَدُكُمْ فِي الصَّلاَةِ آمِينَ وَالْمَلاَئِكَةُ فِي السَّمَاءِ آمِينَ فَوَافَقَ إِحْدَاهُمَا الأُخْرَى غُفِرَ لَهُ مَا تَقَدَّمَ مِنْ ذَنْبِهِ  

The Messenger of Allah ﷺ said: When anyone amongst you utters Amin and the angels In the heaven also utter Amin and (the Amin) of the one synchronises with (that of) the other, all his previous sins are pardoned.  

قَالَ رَسُولُ اللَّهِ ﷺ إِذَا قَالَ أَحَدُكُمْ آمِينَ وَالْمَلاَئِكَةُ فِي السَّمَاءِ آمِينَ فَوَافَقَتْ إِحْدَاهُمَا الأُخْرَى غُفِرَ لَهُ مَا تَقَدَّمَ مِنْ ذَنْبِهِ  

'A hadith like this is transmitted by Ma'mar from Hammam b. Munabbih on the authority of Abu Huraira who reported it from the Messenger of Allah ﷺ.  

عَنِ النَّبِيِّ ﷺ بِمِثْلِهِ  

The Messenger of Allah ﷺ said: When the reciter (Imam) utters:" Not of those on whom (is Thine) wrath and not the erring ones," and (the person) behind him utters Amin and his utterance synchronises with that of the dwellers of heavens, all his previous sins would be pardoned.  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ إِذَا قَالَ الْقَارِئُ غَيْرِ الْمَغْضُوبِ عَلَيْهِمْ وَلاَ الضَّالِّينَ فَقَالَ مَنْ خَلْفَهُ آمِينَ فَوَافَقَ قَوْلُهُ قَوْلَ أَهْلِ السَّمَاءِ غُفِرَ لَهُ مَا تَقَدَّمَ مِنْ ذَنْبِهِ