Stephen quoted the Lord as He spoke to Moses,

“I have surely seen the oppression of My people who are in Egypt; I have heard their groaning and have come down to deliver them. And now come, I will send you to Egypt” (Acts 7:34).

The Lord saw the affliction of the Israelites, heard them groaning over their suffering, and commissioned Moses to deliver them, a man whom they had rejected forty years earlier.

Stephen was setting them up to show how they had done the same thing to Jesus of Nazareth, rejected the One whom God had selected to deliver them from the bondage of sin.