The engulfing oath (yamin ghamus), which is to swear by Allah that one did or did not do something in the past, while deliberately lying about it, is a major sin so enormous that no expiation is due, since expiation is not enough to lift the sin. Rather, one must make sincere repentance and seek Allah’s forgiveness.
Almighty Allah knows best.
Views expressed by hosts/guests on this program (live dialogue, Facebook sessions, etc.) are their own and their appearance on the program does not imply an endorsement of them or any entity they represent.