Matthew 13:51-52 (ESV)
"Have you understood all these things?" They said to him, "Yes." And he said to them, "Therefore every scribe who has been trained for the kingdom of heaven is like a master of a house, who brings out of his treasure what is old and what is new."
I think this parable has many layers of meaning. The old and new treasures are the old prophecies being fulfilled in the new revelation of Jesus. I think they are also an indication that Jesus came to save the old guard (the Jews) and welcome in a new chosen people (the world). I also think it's a subtle reminder to us that there is great value both in old traditions and in new methodology.