Various situations in which an Israelite tries to lead other Israelites into serving other gods all end with capital punishment.
Knowing that Canaanites were not the only threat to covenantal fidelity, this chapter presents three instances where an Israelite might seek to lead other Israelites to worship other gods. In the first instance, a dreamer or miracle worker might arise and give signs that the Israelites should follow another god. But this is a test from God to see if the people will be truly faithful to the God who brought them out of slavery. Regardless of the miracles or signs, those who incite the Israelites to worship other gods are to be put to death.
In shockingly intimate terms, the next section warns against close family members turning Israelites away from God. If invited to idolatry by “…your brother – your mother’s son – your son or daughter, the wife [you hold] in your chest, your friend who is like your own soul… you shall not listen to him, your eye shall not pity him, nor shall you spare or conceal him. Instead, you shall most certainly kill [Hebrew literally, “killingly kill”] him” (Deuteronomy 13:6, 8-9). Indeed, the hand of the closest witness was to be the first to cast a stone. The instruction to show no pity to even those closest to each person would no doubt have been relevant during late Judahite monarchy when faithful kings – Judean king noted for his reforms in time of Isaiah More for example – gave birth to idolatrous sons, such as Manasseh (2 Kings 20-21).
If idolatry takes hold in a city, the matter is to be investigated, searched out, and inquired about thoroughly. If the thorough, ongoing examination bears out that idolatry has become endemic in the town, the entire population of that town is to be destroyed, men, women, children, and animals. Then all the goods of the town were to be gathered and burned in the center of the city, along with all the buildings. The city was to be a ruin forever and never rebuilt. Like the horror of the previous example of loved ones executing the idolator without pity, the complete destruction of the town was to be a warning to other Israelites not to let worship of other gods gain any sort of foothold in Israelite (and therefore Judahite) society. Again, it is probably best to read these passages in light of the idolatry of Manasseh and Amon in the final years of pre-exilic Judahite monarchy.