He replied:

Praise be to Allah. This is not part of the Sunnah of the Messenger of Allah, may Allah bless him and grant him peace, nor has any of the leading Muslim scholars recommended it. However, those who have publicly recited the hadith have done so to instruct people to listen attentively, and this is a kind of sermon. As for the imam’s supplication after ascending the pulpit and the muezzins’ raising their voices in invoking blessings upon the Prophet, the scholars have not mentioned this. Those who practise it do so without any basis in Islamic law. As for the muezzins’ raising their voices during the sermon, whether invoking blessings or saying anything else, this is disliked by agreement of the imams.

He was also asked:

Concerning a muezzin who says, when the preacher enters the congregational mosque:

“Indeed, Allah and His angels send blessings upon the Prophet.”

A man said, “This is a religious innovation.” What, then, is required of him?

He replied:

The muezzin’s reciting this aloud—like his audibly invoking blessings upon the Prophet and asking Allah to be pleased with the Companions when the preacher ascends the pulpit, or audibly supplicating for the preacher and the imam, and similar practices—did not occur during the time of the Messenger of Allah, may Allah bless him and grant him peace, or his Rightly Guided Caliphs. Nor has any of the imams recommended it. Still worse is saying such things aloud during the sermon. All of this is religious innovation, and Allah knows best.