Is the religious lesson before the Friday sermon an innovation (bid‘ah), and is one who attends it sinful if it is an innovation? Is a Muslim sinful if he commits an innovation unknowingly? Is it permissible to shake hands with someone who wants to shake hands after prayer out of embarrassment, or must one refrain from it because it is an innovation?

The scholars dislike studying in the mosque before the Friday sermon, due to the prohibition mentioned in the Sunnah against forming circles before Friday prayer. However, this prohibition signifies a dislike (karahah), not a complete prohibition (tahrim), according to the majority of scholars. If the lesson does not involve breaking rows or causing disturbance, and if it serves a clear benefit, then there is no harm in it. Indeed, it is proven that Abu Hurairah used to narrate Hadith to people before the Friday prayer.

As for forbidden innovation (bid'ah muharramah), the one who commits it, knowing it is forbidden and doing so intentionally, incurs sin. The ignorant person, whose like would be excused for ignorance, is pardoned. As for shaking hands after the salutation of prayer (salam), it is an unsanctioned innovation. However, if someone extends their hand for a handshake, one should not refuse but rather shake their hand, while clarifying that it is not part of the Sunnah.