The third: transitioning from following an imam to praying alone. If there is an excuse, it is permissible; but if there is no excuse, there are two reports from Ahmad, while the madhhab holds that it is invalid (1).

The fourth: transitioning from leading the prayer to praying alone. It has two valid forms (2).

The fifth: transitioning from leading the prayer to following an imam. It has one valid form (3).

The sixth: transitioning from following an imam to leading the prayer. It has two permissible forms, although there is disagreement concerning the second. The details and evidences for this are mentioned in the original work (4).

A follower’s prayer is invalidated when his imam’s prayer is invalidated; therefore, no replacement imam may be appointed.

His statement: “A follower’s prayer is invalidated when his imam’s prayer is invalidated; therefore, no replacement imam may be appointed.”

The follower’s prayer is connected to the imam’s prayer. This is why the imam bears many matters on behalf of the follower, including the first tashahhud: if the imam forgetfully rises without sitting for it, the follower is required to follow his imam, due to the hadith of Abdullah ibn Buhaynah, may Allah be pleased with him, that the Prophet ﷺ led them in the Dhuhr prayer and rose after two rak'ahs without sitting, so the people rose with him (5).

Another is the sitting known as the rest sitting, for the imam