Is it permissible to establish the prayer before the Imam takes his place in the rows, or before it is determined who will lead the prayer if there is no designated Imam?

If a mosque has a regular Imam, it is not permissible to start the prayer before his arrival, unless he is late beyond his usual time. In that case, he should be sent for. If he is near and it is not difficult to bring him, then he should be sent for. But if he is far away and it is highly probable that he will not arrive, or it is known that he would not mind someone else leading the prayer, then they should pray.

If the regular Imam cannot attend, or if there is no Imam at all, then the person present who has memorized the Book of Allah (the Qur'an) the most should be put forward to lead the prayer.

The presence of discussion after the Iqamah (call to commence prayer) to determine who will lead the people in prayer does not harm, as long as it does not result in an unusually long interval between the Iqamah and the prayer. A lengthy separation is disliked by many scholars, and some even stipulate its absence for the validity of the Iqamah.