What does Acts 23:21 mean?
A young man, Paul's nephew, is before the local Roman tribune, warning him of a plot to kill Paul. The tribune—Lysias—rescued Paul from a crowd trying to kill him (Acts 21:30–34). Lysias has spent the last three days trying to figure out if Paul is at fault and should be in prison. He has already taken Paul to the Sanhedrin once and learned nothing except that Paul is smarter than the Jewish ruling council (Acts 23:1–10). Lysias would probably welcome an opportunity to return if he could get to the bottom of the issue.Unbeknownst to Lysias, the Sanhedrin is about to offer such an invitation. The Sanhedrin, in turn, don't know that Paul's nephew knows their request is part of a plot to murder Paul (Acts 23:12–16). We're not sure who the forty men are. They're called "the Jews" which usually refers to Jewish religious leaders, like the scribes of the sect of Pharisees. But Paul's original accusers were Jews from the province of Asia in southwest modern-day Turkey (Acts 21:27). Either way, Paul's life is in danger and since he's a Roman citizen, the tribune must protect him.
Lysias realizes that this case is more than he is authorized to handle. He decides to send Paul to Caesarea Maritima, on the coast of Samaria, to the governor's palace (Acts 23:23–24). The governor will have more resources to discover what Paul has done. And if he doesn't, that absolves Lysias' failure, as well.