- Moving in unison with him.
- Following him.
The first is preceding the imam. We have already established that this is prohibited and among the major sins, as indicated by the sunnah.
There is also a rational indication for this: the imam is an imam, and an imam is one who is to be followed. If you precede him, the imam becomes the follower.
The second is lagging behind the imam.
Lagging behind the imam is of two types:
- Lagging behind due to an excuse.
- Lagging behind without an excuse.
As for the first type—when it is due to an excuse—the follower makes up what he has fallen behind in and then follows the imam, with no blame upon him, even if he has fallen behind by one complete pillar or two. Thus, if someone becomes absent-minded or inattentive, or does not hear his imam until the imam has preceded him by one pillar or two, he performs what he has fallen behind in and follows his imam—unless the imam reaches the same position in which he is. In that case, he does not perform it, but remains with the imam. His rak‘ah is then valid as one composite rak‘ah formed from two rak‘ahs of his imam: the rak‘ah in which he fell behind and the rak‘ah which the imam has reached, while he remains in his position.
An example of this is a man praying with the imam. The imam bows, rises, prostrates, sits, performs the second prostration, and rises until he is standing, while the follower does not hear the one pronouncing the takbīr until the second rak‘ah—for instance, because of a power outage. Let us suppose that this occurs during the Friday prayer: he could hear the imam reciting al-Fātiḥah, then the power went out, and the imam completed the first rak‘ah and stood, while he thought that the imam had not