Hadith on Praise: The reward for praising Allah during prayer is forgiveness of minor sins

Abu Huraira reported: The Messenger of Allah, peace be upon him, said, “When the prayer leader says, ‘Allah listens to those who praise him,’ you should say, ‘O Allah, our Lord for You is the praise.’ If anyone says this when the angels say it, then his previous (minor) sins will be forgiven.”

[Sahih Muslim, Book 4, Number 809]

عَنْ أَبِي هُرَيْرَةَ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ إِذَا قَالَ الْإِمَامُ سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ فَقُولُوا اللَّهُمَّ رَبَّنَا لَكَ الْحَمْدُ فَإِنَّهُ مَنْ وَافَقَ قَوْلُهُ قَوْلَ الْمَلَائِكَةِ غُفِرَ لَهُ مَا تَقَدَّمَ مِنْ ذَنْبِهِ

صحيح مسلم كتاب الصلاة باب التسميع والتحميد والتأمين