Charles Ellicott Commentary Acts 7:41

"And they made a calf in those days, and brought a sacrifice unto the idol, and rejoiced in the works of their hands." — Acts 7:41 (ASV)

They made a calf: The fact is stated in a compound word which is not found in the LXX. version, and which St. Stephen apparently coined for the purpose.

Rejoiced in the works of their own hands: The verb expresses specially the joy of a feast, as in Luke 15:23-24, Luke 15:29, and Luke 16:19, and is therefore specially appropriate for what is related in Exodus 32:5-6. The tense “were rejoicing” expresses the frequency or continuance of the sin.