What is the ruling for the Imam to stand in the middle?

The rule for the Imam's standing is that he should be in the middle of the row. If the right and left sides are equal, the worshipper should complete the right side. The intention is for the congregation to form two groups, to the right and left of the Imam, with the Imam in their middle. This is because the Sunnah is for the Imam to stand in the middle of the row, as this is a requirement of justice. It is not just for the Imam to stand on the far left of the row while all the people are to his right.