1 Kings 12:28, 30, 33

So the king took counsel and made two calves of gold. And he said to the people, “You have gone up to Jerusalem long enough. Behold your gods, O Israel, who brought you up out of the land of Egypt.”

Then this thing became a sin, for the people went as far as Dan to be before one.

He went up to the altar that he had made in Bethel on the fifteenth day in the eighth month, in the month that he had devised from his own heart. And he instituted a feast for the people of Israel and went up to the altar to make offerings.