“And they will recompense your lewdness on you, and you will bear the sins of your idols. And you will know that I am the Lord Yahweh.”
The enemy will carry out God's judgment. They will punish Jerusalem and Samaria for their behaviour. And God's erstwhile people will receive the punishment that they deserve for their idolatry. Thus will they be made to recognise Who and What Yahweh really is, that He is the covenant God and requires full obedience to His covenant.