Sforno on Deuteronomy 13:11/ספורנו על דברים י״ג:י״א

1כי בקש להדיחך, even though he did not cause tangible damage, and therefore might have thought himself immune from prosecution, as opposed to the person who incited to idolatry in the Ir Hanidachat, a city whose majority became idolaters. He is guilty of the death penalty כי בקש להדיחך, because of his attempt to convert people to idolatry. His execution will prevent him from seducing still others. Failure to execute him might result in his success.