And this thing became a sin
The cause and occasion of the sin of idolatry; it led them by degrees to leave off the worship of God, and to worship these calves as gods:
for the people went to worship before the one, even unto Dan;
which was the furthest off, such was their great zeal for idolatrous worship; or they went thither before that at Bethel was set up; and even they at Bethel would go as far as Dan to worship, such was their veneration for both the calves. Abarbinel is of opinion that these calves were not made by Jeroboam for idolatrous uses, only the altar later mentioned; and that he never worshipped before them, nor sacrificed to them, nor even built the altar before them; but that these were set up as signs, and in memory of his kingdom, like the pillars in Solomon's temple; that he chose the calf or ox as emblems of his family, the family of Joseph, ( Deuteronomy 33:17 ) two to represent Ephraim and Manasseh; golden ones, to denote the majesty and perpetuity of his kingdom; and he set these, the one at Bethel, at the entrance of it, and the other at Dan, at the further borders of it; and that he did not call those gods, but the only true God, as he that brought Israel out of Egypt; only signified by that expression, that he was everywhere, there as well as at Jerusalem; but that the Israelites, who were taken with sensible objects, on visiting these out of curiosity, it became a snare to them, and they fell into the worship of them; just as Gideon's ephod, and Moses' brasen serpent, were unto them.