Sunan an-Nasa'i, Hadith 969 ⓘ
It was narrated that 'Ata said: "Abu Hurairah said: "In should be recitation in every prayer. What the Messenger of Allah made us hear (by reciting out loud) we make you hear, and what he hid from us (by reciting silently) we hide from you.'"
أَخْبَرَنَا مُحَمَّدُ بْنُ قُدَامَةَ، قَالَ حَدَّثَنَا جَرِيرٌ، عَنْ رَقَبَةَ، عَنْ عَطَاءٍ، قَالَ قَالَ أَبُو هُرَيْرَةَ كُلُّ صَلاَةٍ يُقْرَأُ فِيهَا فَمَا أَسْمَعَنَا رَسُولُ اللَّهِ صلى الله عليه وسلم أَسْمَعْنَاكُمْ وَمَا أَخْفَاهَا أَخْفَيْنَا مِنْكُمْ .
also referenced under: Book 11, Hadith 94 (In-Book) & Volume 2, Book 11, Hadith 970 (DarusSalam)