What does Acts 7:31 mean?
In the previous section, Stephen tore down the argument that Moses was always worthy of respect. He murdered an Egyptian, earned the derision of the Israelites, and fled from Pharaoh for forty years (Acts 7:23–29). Now, Stephen shows why Moses became worthy of respect: because God chose him to be. While tending his father-in-law's sheep, Moses came upon a bush, on fire but not burned, and "the angel of the LORD" in the midst of the flames. The Old Testament seems to make a distinction between "an angel of the LORD" and "the angel of the LORD." Scholars believe the latter is often the pre-incarnate Christ. That makes sense as the angel of the Lord is in the fire in the bush and God called out to Moses from the bush (Exodus 3:1–4).It is this voice of God that gives Moses authority. He says, "I have surely seen the affliction of my people who are in Egypt, and have heard their groaning, and I have come down to deliver them. And now come, I will send you to Egypt" (Acts 7:34). The Jews in Stephen's audience think they respect Moses, but Stephen reminds them: God commissioned Moses to rescue the Israelites and the Israelites rebelled against him (Acts 7:39–41). In the same way, this Moses told them that God would send another prophet like him (who would be the Messiah), and this same voice of God validated Jesus (Mark 1:9–11; John 1:32–34; 12:28). But Stephen's audience killed Him (Acts 7:52).
Stephen's accusers are devout Jews from northern Africa and modern-day Asia Minor. They have traveled at great expense to come to Jerusalem to worship at the temple. They should know Samuel's words: "Has the LORD as great delight in burnt offerings and sacrifices, as in obeying the voice of the LORD? Behold, to obey is better than sacrifice, and to listen than the fat of rams" (1 Samuel 15:22). And the words of Jeremiah who quoted God: "For in that day I brought them out of the land of Egypt, I did not speak to your fathers or command them concerning burnt offerings and sacrifices. But this command I gave them: 'Obey my voice, and I will be your God, and you shall be my people. And walk in all the way that I command you, that it may be well with you'" (Jeremiah 7:22–23). It was never the burnt offerings, the temple, or even the Law that pleased God; it was always having faith in His words.
His words, throughout Israel's history, pointed to Jesus.