text: It's always good to point out the sometimes radical disagreements among authors of New Testament documents, such as those between Matthew and Paul. E.g. Matthew's allegory of the Last Judgment, in 25.31ff., makes absolutely no sense from a Pauline perspective.
  
  Though Matthew is the only source for the saying in 5.28, I suspect it goes back to the historical Jesus, or at least was inspired by something he said. He was wrapped in an apocalyptic/eschatological vision that assured him (wrongly) that the end of this world was coming very soon. Therefore much that he said has a radical urgency to it. But Paul too shares that vision, when comes his advice in 1 Corinthians 7.8f., it's better to remain single, but then again, "it's better to marry than burn."
  
  This also shows that Jesus was not at all interested in legislating rules for a church lasting indefinitely in time. And so the church has been foolish, and still is, to look for precise instructions on how to behave in his words.