Qur'an 49:3 · Al-Hujuraat

إِنَّ ٱلَّذِينَ يَغُضُّونَ أَصْوَٰتَهُمْ عِندَ رَسُولِ ٱللَّهِ أُو۟لَٰٓئِكَ ٱلَّذِينَ ٱمْتَحَنَ ٱللَّهُ قُلُوبَهُمْ لِلتَّقْوَىٰ ۚ لَهُم مَّغْفِرَةٌۭ وَأَجْرٌ عَظِيمٌ

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