Is it obligatory for worshipers to repeat the Friday prayer as four rak'ahs in their homes by order of the preacher after the prayer due to the possibility that he was not in a state of ritual purity?

If the Imam doubts his ritual purity after the prayer has concluded, his prayer and the prayer of those led by him are valid, as long as he performed ablution before the prayer. This is because the original state is the continuation of ablution, and doubt does not remove it.

If the Imam is certain that he was in a state of ritual impurity after the prayer, he must repeat it, but the prayer of those led by him remains valid.

However, if the Imam became aware of his ritual impurity during the prayer and completed it, it is more cautious for those led by him to repeat the prayer. If the time for the Friday prayer has passed, they should pray Dhuhr. If it has not passed, the Imam should perform ablution or appoint someone else, and they should pray the Friday prayer as two rak'ahs.