Deuteronomy 29:24-26

24All the nations will ask: “Why has the LORD done this to this land? Why this fierce, burning anger?” 25And the answer will be: “It is because this people abandoned the covenant of the LORD, the God of their ancestors, the covenant he made with them when he brought them out of Egypt. 26They went off and worshiped other gods and bowed down to them, gods they did not know, gods he had not given them.