The Messenger of Allah ﷺ retired to the mosque. He heard them (the people) reciting the Qur'an in a loud voice. He removed the curtain and said: Lo! every one of you is calling his Lord quietly. One should not trouble the other and one should not raise the voice in recitation or in prayer over the voice of the other. (Using translation from Abū Dāʾūd 1332)   

اعْتَكَفَ النَّبِيُّ ﷺ فِي الْمَسْجِدِ فَسَمِعَهُمْ يَجْهَرُونَ بِالْقِرَاءَةِ وَهُوَ فِي قُبَّةٍ لَهُ فَكَشَفَ الْمَسْتُورَةَ وَقَالَ أَلَا إِنَّ كُلَّكُمْ يُنَاجِي رَبَّهُ فَلَا يُؤْذِيَنَّ بَعْضُكُمْ بَعْضًا وَلَا يَرْفَعَنَّ بَعْضُكُمْ عَلَى بَعْضٍ فِي الْقِرَاءَةِ فِي الصَّلَاةِ  

[Machine] That the Messenger of Allah ﷺ came out to the people while they were praying and their voices were raised in recitation, so he said: "Verily, the one who prays is having a private conversation with his Lord, so let him look towards what he is conversing with Him, and do not raise your voices over one another in recitation."  

أَنَّ رَسُولَ اللهِ ﷺ خَرَجَ عَلَى النَّاسِ وَهُمْ يُصَلُّونَ وَقَدْ عَلَتْ أَصْوَاتُهُمْ بِالْقِرَاءَةِ فَقَالَ إِنَّ الْمُصَلِّيَ مُنَاجٍ رَبَّهُ فَلْيَنْظُرْ مَا يُنَاجِيهِ بِهِ وَلَا يَجْهَرْ بَعْضُكُمْ عَلَى بَعْضٍ بِالْقِرَاءَةِ