The Sermon on the Mount is some of Jesus’s cornerstone teaching. It is not meant as some kind of checklist.. “be poor in Sprit, be pure in heart, etc.” but as an endorsement of the least among the people. This is why it is connected to having greater righteousness than the Pharisees (and notice that he said that the Law still stands). Having greater righteousness of the Pharisees is not about policing the Kingdom, it is about following the leader of that Kingdom.