Then the LORD sent a plague on the people, because they made the calf, the one that Aaron made.
35. And the Lord plagued the people Moses here briefly attributes to God what he had before related as to the slaughter of the three thousand, lest any should think that he had smitten them with immoderate severity Therefore Paul bids us consider in this history, as in a mirror, how greatly displeasing to God idolatry is; lest we should imitate those who were smitten by His hand.
Moses calls it a great sin so they will not think themselves innocent, and he shows them how difficult atonement is, he must go up to the Lord himself, and even then perhaps make peace. The malignity of sin appears in the price of pardons. He who undertook to make atonement found it no easy thing to do it.
AI summary
Commenting on Exodus 32:30-35
And when the people saw that Moses delayed to come down out of the mount,.... The time, according to the Targum of Jonathan, being elapsed, which he had fixed for his descent, and through a misreckoning, as Jarchi suggests; they taking the day of his going up to be one of the forty days, at the end of which he was to return, whereas he...