Is it ok to warn someone who recites too loudly while praying?

It is permissible to warn someone who recites too loudly while praying, as there are teachings from the Prophet Muhammad ﷺ that address this behavior. For instance, in a narration from Sunan Ibn Majah, it is reported that The Prophet prayed with his companions one day, and after concluding the prayer, he faced them and said, 'What is wrong with some people who raise their eyes to the heavens during prayer until their voice grows loud? He said this to admonish them to desist or to snatch their gaze away.' Sunan Ibn Majah 6:242SunniSahih (per Al-Albani). This indicates that the Prophet was concerned about the manner of prayer and the need for maintaining proper etiquette, which includes not raising one's voice unnecessarily.

Furthermore, Ibn Kathir explains the importance of attentiveness during prayer, emphasizing that followers should listen attentively and not recite aloud behind the imam during congregational prayers (Tafsir Ibn Kathir). This reinforces the idea that maintaining respect and proper decorum in prayer is essential, and it is acceptable to remind others of this when needed.