EXTRA · Parashas Reeh · Third Aliyah · Passuk 12:30
Supplementary classical material for a passuk with no Torah Temimah citation.
Take heed to yourself lest you be ensnared after them, after they are destroyed from before you, and lest you inquire about their gods, saying, “How did these nations serve their gods? And I will do likewise.”
Classical source: Sanhedrin 60b / Sifrei Devarim.
English: “How did they serve” — Because Scripture punished for idolatry only for slaughter, incense, libation and prostration, it comes here to teach that if the customary way of serving an idol is by some other act (e.g., exposing oneself before Peor or casting a stone before Mercury), that is its service and one is liable.
Derash on the phrase “how did they serve” (Sanhedrin / Sifrei) — the Torah itself defines the prohibited modes of worship.
One is liable for serving an idol in the manner that is customary for that idol, even when the act is not one of the four standard forms of divine service.