Acts 22: Paul's discourse

The crowd in Jerusalem (near the temple) thought that Paul was some kind of helenist guy, that didn´t care about the Lord or the people of Israel. The proof to it was that they thought that Paul was leading some gentiles inside the inner courts of the temple (which would profane the temple). The crowd wanted to kill him, but when Paul was being rescued by the Roman commander in the stairs of of the Fortress of Antonia, he asked the commander to speak some words to the crowd (who was against him). 
His purpose was to explain that his acts were not against the Lord but by the opposite: his acts were in obedience to the Lord.
He began to talk in Aramaic, not in Greek. He began saying about his high level Jewish degrees (education, obedience to the tradition, etc.). In a way, he was far superior in Jewish tradition than the normal crowd. He explained that Jesus (who was crucified and cursed by the Lord) was indeed resurrected and alive.
We read:
21 And He/Jesus said to me, ‘Go! For I will send you far away to the Gentiles.’”
22 They listened to him up to this statement, and then they raised their voices and said, “Away with such a man from the earth, for he should not be allowed to live!”

Why the sentence in 21 made the crowd so angry? 
They always say the Gentiles as the uncleans while they were the chosen people of the Lord. It seemed very offensive to them that the Messiah would accept the Gentiles as his people.
And here I am: a gentile in 2026, that belongs to the Messiah, chosen by the Messiah.