How did the high priest have authority to extradite Christians from Damascus?
The high priest could demand extradition because Judaism had significant clout with the Roman government. The high priest and Israel’s rulers wielded enough influence that certain cities in the Roman Empire allowed them to request the return of fugitives, similar to modern extradition between nations, enabling Saul to pursue followers of Jesus in Damascus.
Les explains that he often wondered how the Romans allowed this. Judaism had a fair amount of clout even with the Romans, and the High Priest and the rulers of Israel had enough clout with the Roman government that with a few of the cities of the Middle Eastern Roman Empire, they could actually demand extradition like we do today. He gives the analogy that if someone from America commits a horrible crime and flees to Canada, the law allows us to prevail on the Canadian government to extradite them back home to America. The Judaizers, the High Priest of Israel, had that kind of control over the Roman government that there were certain cities where they could ask for extradition. So Saul and the religious leaders of Israel kick into gear and say, let us come up to Damascus and bring these renegade Jews who have followed this Jesus of Nazareth, and let us deal with them. Les notes that Paul rehearses in chapter 26 that they threw them into prison and put them to death.