Then Moses stood in the gate of the camp
In one of the gates of it; for it doubtless had more than one to go in and out of, as is clear from ( Exodus 32:27 ) it being probably entrenched all around; here Moses set himself, it being the usual place, as in cities, where the people were summoned together on important occasions, and justice and judgment were administered:
and said, who is on the Lord's side? [let him come] unto me;
who is for the worship of the true God, and him only, and against the worship of a gold calf, or any other idol, and is zealous for the glory of God, and the honour of his name;
and all the sons of Levi gathered themselves together unto him;
that is, all those that had not given in to the idolatry of the calf; all is put for many. Jarchi infers from hence, that this tribe was wholly free from that sin; but the contrary is most evident, for it appears from the context that many of them were slain for it; yea, as, on the one hand, they were only of the tribe of Levi, who joined themselves to Moses, though there was no doubt many in all the tribes that were not in the idolatry; so, on the other hand, there were none slain, or very few, but of the tribe of Levi, as will appear in the exposition of the following verses, the being principally concerned with Aaron in making the calf; and therefore those of the same tribe that joined them not were the more zealous and studious to purge themselves from the imputation of the crime, by going over to Moses at once, and showing themselves to be on the Lord's side.