John Gill Bible Commentary

Thus they changed their glory,.... God, who is glorious in all the perfections of his nature, and is glory itself, and was the glory of these people; it was their greatest honour that they had knowledge of him, nearness to him, the true worship of him among them, and that they were worshippers of him; and who, though he is unchangeable in himself, may be said to be changed when another is substituted and worshipped in his room, or worshipped besides him; which was what the Heathen did, and in which the Israelites exceeded them, Rom 1:23, the Targum is, "they changed the glory of their Lord.'' Into the similitude of an ox that eateth grass; which was monstrous stupidity, to leave the worship of the true God, El Shaddai, God all sufficient, all powerful, that stands in need of nothing, but upholds and supports all creatures in being, and provides them with necessaries; and worship an ox, yea, the figure of one that eats grass, that lives on hay, and is supported by that which is so weak and withering; the Targum adds, "and makes dung;'' or defiles itself with it, as the ox does while it is eating grass; Jarchi observes, there is nothing more abominable and filthy than an ox when it is eating grass, which then makes much dung, and defiles itself; this the Targumist adds, to make the worship of such a creature the more contemptible.