Answered by Shaykh Faraz Rabbani
What happens if the muazin forgets one of the lines of the iqamat? Should he restart again? Should someone jump in and say that line on the muazin’s behalf? Is it OK to start the prayer even if the muazin has not read the iqamat properly.
Answer:
Walaikum assalam wa rahmatullah,
If the muezzin forgets one of the lines of the iqama, he should pause, go back one or two lines in his mind, and continue when he remembers if the pause is short.
If he simply can’t remember the words or if the pause becomes long, then he (or someone else) should re-start.
And Allah alone gives success.
Faraz Rabbani