1 Kings 12:32

In the eighth month, on the fifteenth day of the month... — The “feast that was in Judah,” to which this is said to be like, is clearly the Feast of Tabernacles, on the fifteenth day of the seventh month. The fixing of Jeroboam’s festival of dedication for the Temple at Bethel to this special day is characteristic. It at once challenged likeness to the Feast of Tabernacles, which was (see 1 Kings 8:2) the occasion of Solomon’s dedication at Jerusalem, and yet took liberty to alter the date, and fix it in the month “which he had devised of his own heart,” thus assuming the right to set aside the letter of the old law, while professing still to observe the worship of Jehovah.

Offered — or (see margin) went up — upon the altar. — The expression seems to imply that he ventured on a still greater innovation by taking on himself both functions of the priestly office — to offer sacrifice and (see 1 Kings 12:33) to burn incense. This is not, indeed, necessarily implied; for (see 1 Kings 8:63) the sacrificer is often said to offer, when he evidently does so only through the priests. But Jeroboam had set aside the peculiar sanctity of the Levitical priesthood already; and so was very naturally prepared to crown this process by acting as head of the unauthorised priesthood which he had created. Perhaps he had witnessed the exclusive prominence of Solomon at the great dedication festival, and desired to imitate and outdo it.