Why did the Lord tell Paul to get out of Jerusalem in Acts 22:18?

Les explains that Paul had ministered to Gentiles for some 20 years or more, with a tremendous response and churches established throughout Asia Minor, Greece, and Rome. When he returned to Jerusalem, he nearly was killed by the mob. In Acts 22, before the religious leaders, Paul recounted his conversion on the road to Damascus and his experiences among the Gentiles, how they came to a knowledge of Israel's God through the Gospel and Christ's death, burial, and resurrection. At verse 18, Paul rehearsed that while praying in the temple, in a trance, he saw the Lord say, "Make haste, get thee out of Jerusalem, for they the Jews will not receive thy testimony concerning me." Paul then reminded his Jewish audience that they knew he had imprisoned and beaten believers in every synagogue and had consented to Stephen's death, holding the raiment of those who killed him. In verse 21, Paul says the Lord told him, "Depart, get out of Jerusalem, for I will send you far hence to the Gentiles." Thus, the reason was Jewish rejection of his testimony and the Lord's commission to send him far away to the Gentiles.