Kings III 12:33

33 and went up to the altar which he made in Baethel to sacrifice to the heifers which he made, and he placed in Baethel the priests of the high places which he had made. And he went up to the altar which he had made, on the fifteenth day in the eighth month, at the feast which he devised out of his own heart; and he made a feast to the children of Israel, and went up to the altar to sacrifice.

Kings III 12:33 In-Context

31 And he made houses on the high places, and made priests of any part of the people, who were not of the sons of Levi.

32 And Jeroboam appointed a feast in the eighth month, on the fifteenth day of the month, according to the feast in the land of Juda;

33 and went up to the altar which he made in Baethel to sacrifice to the heifers which he made, and he placed in Baethel the priests of the high places which he had made. And he went up to the altar which he had made, on the fifteenth day in the eighth month, at the feast which he devised out of his own heart; and he made a feast to the children of Israel, and went up to the altar to sacrifice.