The Messenger of Allah ﷺ came out to the people while they were praying, and their voices had risen in recitation. He said, "The one who prays is conversing privately with his Lord , so let him consider what he is saying to Him, and let none of you raise his voice over another in reciting the Quran."
قال قرأت على عبد الرحمن بن مهدي: مالك عن يحيى بن سعيد عن محمد بن إبراهيم التيمي عن أبي حازم التمار
أن رسول الله ﷺ خرج على الناس وهم يصلون وقد علت أصواتهم بالقراءة فقال إن المصلي يناجي ربه عز وجل فلينظر ما يناجيه ولا يجهر بعضكم على بعض بالقرآن
Its isnad is sahih. Abu Hazim the Date-Seller is the freed slave of Abu Rahm Ghifari. Ibn Hibban and Ibn Abdul-Barr both deemed him trustworthy. The hadith was narrated by Abdul-Razzaq, 2/498, no. 4217, in the Book of Prayer, chapter on night recitation, and by Ibn Mubarak in Zuhd, 402, no. 1144, and by Bayhaqi, 3/12. Haythami said, 2/265, "Its narrators are the narrators of the Sahih."