For the source text click/tap here: Sanhedrin 111
To download, click/tap here: PDF
The Mishnah states that the people of an Ir ha'Nidachas have no share in Olam ha'Ba.
Why should they have no share in Olam ha'Ba? The Mishnah earlier (43b) states that part of the process of Misas Beis Din is confession and repentance. Since the people of an Ir ha'Nidachas are put to death by Beis Din, they presumably must have repented immediately before their execution and thereby gained atonement! Moreover, Rava (47a) maintains that those who are killed by Beis Din achieve atonement even if they do not do Teshuvah. Why, then, do the people of an Ir ha'Nidachas have no share in Olam ha’Ba?