Is it permissible for the muezzin to pause briefly after each phrase of the Adhan so that the listeners may repeat after him?

There is no specific text in the Sunnah that commands leaving a gap between the phrases of the adhan for the listener to repeat, but this is understood from the recommended manner of performing the adhan. Among the agreed-upon Sunnahs of the adhan is al-tarsul (deliberateness) in it, which means slowness, clear recitation, avoiding haste, pausing at the end of phrases to catch one's breath. Al-tarsul means pronouncing the adhan clearly, letter by letter, and exhaling with each word. There is no doubt that pausing to take a breath gives the listener an opportunity to repeat. Al-tarsul is the deliberation with a pause sufficient for the response between every two phrases of the adhan. Since the listener is commanded to repeat, the muezzin must be deliberate to enable them to do so.