Sunan An-Nasa'i - سنن النسائي
20. The Book of Qiyam Al-Lail (The Night Prayer) and Voluntary Prayers During the Day - كتاب قيام الليل وتطوع النهار
24) Chapter: The Superiority of reciting silently over reciting loudly
It was narrated from Kathir bin Murrah that 'Uqbah bin 'Amir told them that:
The Messenger of Allah (ﷺ) said: 'The one who recites the Qur'an loudly is like one who gives charity openly, and the one who recites the Qur'an silently is like the one who gives charity in secret.'"
24) باب فَضْلِ السِّرِّ عَلَى الْجَهْرِ
أَخْبَرَنَا هَارُونُ بْنُ مُحَمَّدِ بْنِ بَكَّارِ بْنِ بِلاَلٍ، قَالَ حَدَّثَنَا مُحَمَّدٌ، - يَعْنِي ابْنَ سُمَيْعٍ - قَالَ حَدَّثَنَا زَيْدٌ يَعْنِي ابْنَ وَاقِدٍ، عَنْ كَثِيرِ بْنِ مُرَّةَ، أَنَّ عُقْبَةَ بْنَ عَامِرٍ، حَدَّثَهُمْ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ . " إِنَّ الَّذِي يَجْهَرُ بِالْقُرْآنِ كَالَّذِي يَجْهَرُ بِالصَّدَقَةِ وَالَّذِي يُسِرُّ بِالْقُرْآنِ كَالَّذِي يُسِرُّ بِالصَّدَقَةِ "