Answered by Shaykh Faraz Rabbani
Can the Muezzin say the after-prayer dhikrs out loud?
The sunna is to say these after-prayer dhikrs. It is not specifically a sunna to say them aloud. Rather, what is implicitly understood in the sunna is that these dhikrs are said quietly. However, if there is an interest in the muezzin or imam raising their voice to remind others to say them (normally, by raising their voice for the first instance of each set of dhikrs), then there is no harm in this, as long as it is not deemed to be a specific religious obligation. [Abu Sa`id al-Khadimi, Rasa’il wa Fatawa]
And Allah alone gives success.
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