74 The verse is difficult because of the double reference to the making of the calf. The ’s translation tries to reconcile the two by reading “for what they did with the calf that Aaron had made.” B. S. Childs (Exodus [], 557) explains in some detail why this is not a good translation based on syntactical grounds; he opts for the conclusion that the last three words are a clumsy secondary addition. It seems preferable to take the view that both are true, Aaron is singled out for his obvious lead in the sin, but the people sinned by instigating the whole thing.
75 Most commentators have difficulty with this verse. W. C. Kaiser says the strict chronology is not always kept, and so the plague here may very well refer to the killing of the three thousand (“Exodus,” 2:).

In other versions

Then the Lord sent a plague on the people, because they made the calf, the one that Aaron made.

And the Lord struck the people with a plague because of what they did with the calf Aaron had made.

And the Lord inflicted a plague on the people for what they did with the calf Aaron had made.

Then the Lord sent a great plague upon the people because they had worshiped the calf Aaron had made.

And Yahweh afflicted the people because they had made the bull calf that Aaron had made.

And the Lord plagued the people, because they made the calf, which Aaron made.

Public Domain