Someone who's doing something to you, don't try to seek revenge. And this is a very different tone than a lot of what you might get in the Old Testament. Ye have heard that it was said, thou shalt love thy neighbor and hate thine enemy. But I say unto you, love your enemies and pray for them that persecute you. Once again, not an easy thing to do, and even in modern terms, you could view this as a very forward, a very advanced way of thinking about the world. He also, beyond this idea of kind of embracing even your enemies and not seeking revenge, and that the poor can have access to this kingdom of heaven, he really also liked to take it to the hypocrites, especially those who viewed themselves as the bearers of the religion. In particular, he picks on the Pharisees, which was a sect of Jews at the time who viewed themselves very ritualistic.