1 Kings 12:32

And Jeroboam ordained a feast in the eighth month, on the
fifteenth day of the month, like unto the feast that is in Judah,
&c.] The feast of tabernacles, which was on the fifteenth day of the seventh month; this was done chiefly for the sake of an alteration; though Abarbinel thinks, because the fruits of the land were not so soon ripe nor so soon gathered, in the northern parts of the land, as nearer Jerusalem, he judged this month the fittest for the feast of ingathering the fruits; and he might hope to get more people to come to his feast, when all were gathered in:

and he offered upon the altar (so he did in Bethel), sacrificing unto
the calves that he had made:
this he did by his priests, or rather he himself did it, see ( 1 Kings 13:4 ) , this shows that Jeroboam made these calves for worship, and did sacrifice to them, at least as representations of God. Abarbinel, to make this agree with his hypothesis, gives this sense of the clause, that he did not sacrifice to the calves, but to God, because of them, that his kingdom, which they were a sign of, might be continued; and there being but one calf in a place, he could not be said to sacrifice to them both, but to God, because of both; or else he thinks this must be done after the people had turned aside to them, and not when Jeroboam made them. The clause in the parenthesis, "so he did in Bethel", intimates that he did the same in Bethel as in Dan, of which what is said before is spoken; that is, that he made an house of high places in Bethel also, made priests out of all the people, such as were not of the tribe of Levi, appointed the feast of the fifteenth day of the eighth month to be observed there also, and he himself offered on the altar there:

and he placed in Bethel the priests of the high places which he had
made:
to officiate there.