1 Kings 12:31

29He set the one in Bethel, and the other he put in Dan.

30This thing became a sin, for the people went even as far as Dan to worship before the one there.

31He made houses of high places, and made priests from among all the people, who were not of the sons of Levi.

32Jeroboam ordained a feast in the eighth month, on the fifteenth day of the month, like the feast that is in Judah, and he went up to the altar. He did so in Bethel, sacrificing to the calves that he had made, and he placed in Bethel the priests of the high places that he had made.

33He went up to the altar which he had made in Bethel on the fifteenth day in the eighth month, even in the month which he had devised of his own heart; and he ordained a feast for the children of Israel, and went up to the altar to burn incense.