(Al-Hujurath) 49 : 2
يَا أَيُّهَا الَّذِينَ آمَنُوا لَا تَرْفَعُوا أَصْوَاتَكُمْ فَوْقَ صَوْتِ النَّبِيِّ وَلَا تَجْهَرُوا لَهُ بِالْقَوْلِ كَجَهْرِ بَعْضِكُمْ لِبَعْضٍ أَنْ تَحْبَطَ أَعْمَالُكُمْ وَأَنْتُمْ لَا تَشْعُرُونَ
Oh, you who believed! You shouldn’t raise your voices above the voice of the Prophet, and you shouldn’t be loud to him with words just like you speak loudly to one another among you, lest your deeds become futile while you perceive it not.
Since the believer who has understood that whatever the Messenger talks is Adhikr, and it is just like Allah talks, he does not talk loudly as if he doesn’t hear what the Messenger talks, or does not talk in a manner that it would make hindrance to hearing the Messenger’s speeches to others. Contrary to this, if the believer talks or does against the messages of the verses such as 8: 35; 17: 110; 31: 19; and 41: 26, all his deeds will become futile. See explanation 7: 203-205; 47: 1-3; and 53: 1-4.