John Calvin Commentary Acts 7:39

"to whom our fathers would not be obedient, but thrust him from them, and turned back in their hearts unto Egypt," — Acts 7:39 (ASV)

They refused, and were turned away. He says that the fathers rejected Moses; he also shows the cause, namely, that they gave themselves over instead to the superstitions of Egypt. It was horrible, and more than blind fury, for them to desire the customs and ordinances of Egypt, where they had recently suffered such grievous things.

He says that they were turned away to Egypt in their hearts; not that they desired to return there bodily, but because they returned in mind to those corruptions, which they should not even have remembered without great detestation and hatred. It is true, indeed, that the Jews did once speak of returning, but Stephen does not address that history now.

Furthermore, he instead expresses their stubbornness when he says that they were turned away. For after they had taken the right way, having God for their guide and governor, they suddenly start aside, as if a stubborn, unbroken horse, not obeying its rider, should stubbornly run backward.