This verb appears in the exodus stories, describing God “hardening” Pharaoh’s heart (Exodus 4:21; Exodus 9:12; Exodus 10:20, Exodus 10:27; Exodus 11:10; Exodus 14:4, Exodus 14:8) and the Egyptians’ heart (Exodus 14:17). Its usage here, then, bodes ill for God’s people.
12 And the people of Israel again did what was evil in the sight of the LORD, and the LORD strengthened Eglon the king of Moab against Israel, because they had done what was evil in the sight of the LORD.