Jesus’ first priority in his Sermon on the Mount (Hill) was to reveal that those whom the world least values, respects, and understands are the first people welcomed and blessed in His kingdom.
John the baptist was the forerunner for Jesus who proclaimed “Repent, for the kingdom of God is near.” The kingdom of God is God’s presence in our reality.
Matthew is drawing on the Old Testament prophecies to show how Jesus will fulfill the need for a Messiah to come and save and restore the people of Israel in a way we would hardly want or recognize.