Does the prayer of an imam who shaves most of his beard, leaving only a thin strip of it, invalidate his prayer and consequently the prayer of those praying behind him? And if his prayer is valid, should he be replaced by another imam, even if the latter has not memorized the Qur’an?

Firstly, the prayer of one who shaves his beard is valid if he performs it as Allah has legislated, and the prayer of those behind him is valid if he leads the prayer, by the consensus of the scholars. This is evidenced by the prayer of the Companions behind oppressive imams like Al-Hajjaj. There is no weight to the opinion of those who say it is obligatory not to pray behind a corrupt imam; rather, it is obligatory to pray behind him if not praying behind him would lead to corruption or division.

Secondly, replacing the imam who shaves his beard is preferable if possible, with an imam who adheres more closely to religious practices, without causing a greater mischief. Otherwise, his retention is more preferable. The evidence for preventing an imam who openly commits sins from leading prayer is the hadith (definition) about the man who spat towards the qibla (definition). However, this prevention is conditional on not resulting in a greater mischief; if it would, then it is obligatory to pray behind him. It is not permissible to abandon congregational prayer due to the imam's corruption.