An image — The image of that Baal which was worshipped in the grove.
Related Commentaries of 2 Kings 21:7
2 Kings 21:7
7 And he set a graven image of the grove that he had made in the house, of which the LORD said to David, and to Solomon his son, In this house, and in Jerusalem, which I have chosen out of all tribes of Israel, will I put my name for ever: