1 Kings 12:28-32

28And the king took counsel, and made two calves of gold. And he said to them, It is too much for you to go up to Jerusalem: behold thy 1gods, Israel, which brought thee up out of the land of Egypt!

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

30And this thing became a sin; and the people went [to worship] before the one, as far as Dan.

31And he made a house of high places, and made priests from all classes of the people, who were not of the sons of Levi.

32And Jeroboam ordained a feast in the eighth month, on the fifteenth day of the month, like the feast that was in Judah, and he offered upon the altar. So did he 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.