The learned scribe brings forth both the new and the old. (see Matthew 13:52)
What does the Lord mean here? What is “the new,” and what is “the old?”
Answering “the Old Covenant and the New Covenant!” or “the Old Testament and the New Testament,” puts you in good company. St. Augustine interpreted the verse that way.
During St. Augustine’s time, and up to this very day, some Christians erroneously have dismissed the Old Testament as barbaric, flawed, and unnecessary. So St. Augustine understood the Lord Jesus to be saying in this verse: My disciples need to study and try to understand both the New and the Old Testaments. We cannot grasp the divine mystery without both.
What about St. Gregory the Great? He understood “new” and “old” differently.
The “old” truth, which is still true, is: The human race deserves condemnation and punishment because of our sins.
The “new” truth is: We can repent and be converted. We can live in the sweetness of the kingdom of the Lamb.