Those who instinctively lower their voices in the presence of Allah’s noble Messenger have hearts well proven by Allah to be full of holiness and devotion. Theirs is the complete Divine Forgiveness and the most sublime Divine Reward.
إِنَّ الَّذِينَ يَغُضُّونَ أَصْوَاتَهُمْ عِنْدَ رَسُولِ اللَّهِ أُولَٰئِكَ الَّذِينَ امْتَحَنَ اللَّهُ قُلُوبَهُمْ لِلتَّقْوَىٰ ۚ لَهُمْ مَغْفِرَةٌ وَأَجْرٌ عَظِيمٌ
Innal lazeena yaghud doona aswaatahum 'inda Rasoolil laahi ulaaa'ikal lazeenam tah anal laahu quloobahum littaqwaa; lahum maghfiratunw wa'ajrun 'azeem