How do we know Jesus appeared to Old Testament figures?

In his defense, Stephen refers to significant moments in Israel's history where the presence of the Lord Jesus is implied. For instance, in Acts 7:2, Stephen speaks of God appearing to Abraham, which he attributes to Jesus. He continues this theme with references to Moses and the burning bush in verse 32, where the voice speaking was the Lord. Moreover, the prophets foretold of the coming of the Just One, which the Sanhedrin had betrayed and murdered. Stephen's testimony is a profound evidence that Jesus was at work long before His incarnation, recognizing Him as the central figure in God's redemptive plan throughout history.