13:10
سَوَآءٌ مِّن كُم مَّنْ أَسَرَّ ٱلْ قَوْلَ وَ مَن جَهَرَ بِ هِۦ وَ مَنْ هُوَ مُسْتَخْفٍۭ بِ ٱلَّ يْلِ وَ سَارِبٌۢ بِ ٱل نَّهَارِ
It is the same [to Him] concerning you whether one conceals [his] speech or one publicizes it and whether one is hidden by night or conspicuous [among others] by day.
17:110
قُلِ ٱدْعُ وا۟ ٱللَّهَ أَوِ ٱدْعُ وا۟ ٱل رَّحْمَٰنَ أَيًّا مَّا تَدْعُ وا۟ فَ لَ هُ ٱلْ أَسْمَآءُ ٱلْ حُسْنَىٰ وَ لَا تَجْهَرْ بِ صَلَاتِ كَ وَ لَا تُخَافِتْ بِ هَا وَ ٱبْتَغِ بَيْنَ ذَٰلِكَ سَبِيلًا
Say, "Call upon Allah or call upon the Most Merciful. Whichever [name] you call - to Him belong the best names." And do not recite [too] loudly in your prayer or [too] quietly but seek between that an [intermediate] way.
20:7
وَ إِن تَجْهَرْ بِ ٱلْ قَوْلِ فَ إِنَّ هُۥ يَعْلَمُ ٱل سِّرَّ وَ أَخْفَى
And if you speak aloud - then indeed, He knows the secret and what is [even] more hidden.
49:2
يَٰٓ أَيُّهَا ٱلَّذِينَ ءَامَنُ وا۟ لَا تَرْفَعُ وٓا۟ أَصْوَٰتَ كُمْ فَوْقَ صَوْتِ ٱل نَّبِىِّ وَ لَا تَجْهَرُ وا۟ لَ هُۥ بِ ٱلْ قَوْلِ كَ جَهْرِ بَعْضِ كُمْ لِ بَعْضٍ أَن تَحْبَطَ أَعْمَٰلُ كُمْ وَ أَنتُمْ لَا تَشْعُرُ ونَ
O you who have believed, do not raise your voices above the voice of the Prophet or be loud to him in speech like the loudness of some of you to others, lest your deeds become worthless while you perceive not.
67:13
وَ أَسِرُّ وا۟ قَوْلَ كُمْ أَوِ ٱجْهَرُ وا۟ بِ هِۦٓ إِنَّ هُۥ عَلِيمٌۢ بِ ذَاتِ ٱل صُّدُورِ
And conceal your speech or publicize it; indeed, He is Knowing of that within the breasts.