ויקרא

ואת הבהמה תהרגו. פירש רש"י ז"ל אם אדם חטא בהמה מה חטאה אלא מפני שבאה לאדם תקלה על ידה, לפיכך אמרה תורה תסקל, קל וחומר למי שיודע להבחין בין טוב לרע וגורם תקלה לחברו לעבור עברה על אחת כמה וכמה. כיוצא בדבר אתה אומר (דברים י״ב:ב׳) אבד תאבדון את כל המקומות, קל וחומר ומה האילנות שאינן רואין ולא שומעין על שבאה תקלה על ידן אמרה תורה השחת שרוף וכלה, המתעה חברו על אחת כמה וכמה.

ואת הבהמה תהרגו, “and the beast you shall kill.” Rashi, following our sages, asks the rhetorical question why the animal should be killed seeing it had not committed a crime? The answer given is that seeing the animal was the catalyst leading to the sin by the human being involved in the act the Torah decreed that it be stoned to death. You may apply some logic here. If even an animal which is unable to distinguish between right and wrong is executed, how much more so will execution be the penalty for a human being who does know right from wrong. When a human being is the cause of a fellow human committing a sin, he is certainly culpable for what he did. We have a verse in Deut. 12,2 where the Torah commands us to destroy all the sites on which idolatry was performed by the Canaanites prior to the Israelites coming to the Holy Land. This provides us with a similar reason of why humans guilty of idolatry will be subject to the death penalty. If even trees, which most certainly were totally passive and had no knowledge of something sinful being performed involving them, are subject to destruction on account of this, how much more so are human beings who were the cause of another human being induced to worship idols through deceiving such a person, subject to execution for their deeds?