It is not clear exactly which law Shecaniah was referring to. Deuteronomy 7:3–4 forbade the Israelites from marrying foreign women, but there is no specific law that then explains what must be done if Israel sins in this way.1
There are two laws that may have motivated the decision. Leviticus 18:29 determined that anyone who engaged in the unclean sexual practices that the Canaanites were famous for was to be cut off from God’s people. Similarly, Deuteronomy 13:6–11 also specified that anyone who encouraged the worshipping of idols was to be killed by stoning.
3 Therefore let us make a covenant with our God to put away all these wives and their children, according to the counsel of my lord and of those who tremble at the commandment of our God, and let it be done according to the Law.