R. Eliezer says: "elohim acherim": They "renew" gods for themselves every day. How so? If one had a golden god and he needed gold, he make it of silver. If he needed that, he made if of copper. If he had a copper god and he needed copper, he made it of iron or of lead. And thus is it written (Devarim 32:17) "new ones (gods), newly come."