AL HUJURAAT — Ayat 3

إِنَّ الَّذِينَ يَغُضُّونَ أَصْوَاتَهُمْ عِندَ رَسُولِ اللَّهِ أُوْلَئِكَ الَّذِينَ امْتَحَنَ اللَّهُ قُلُوبَهُمْ لِلتَّقْوَى لَهُم مَّغْفِرَةٌ وَأَجْرٌ عَظِيمٌ

Indeed, those who lower their voices before the Messenger of Allah - they are the ones whose hearts Allah has tested for righteousness. For them is forgiveness and great reward.