What does Matthew 13:52 mean?

Parables, by definition, summarize a larger idea using symbolism and storytelling. That makes large ideas easier to process, but it also obscures specific details. This miniature parable is not especially clear, in part because Matthew does not record any specific interpretation. Scholars offer different views. The main point, common to all interpretations, involves the need to explain both the Old Testament prophecies and their accurate fulfillment in the New Testament era.

Christ has asked the disciples if they understood His explanation of the parables. They have said they do (Matthew 13:51). Now He responds by referring to scribes, who, at that time, were Israel's teachers of the law. They studied and interpreted Scripture and told the people the proper way to live by it. In a very meaningful sense, these disciples are being taught deeper truths by Jesus (Matthew 13:10–11), and so are like "[scribes] trained for the kingdom of heaven." As such, the disciples' work would be to teach these truths to others (Matthew 28:19–20), both "old" and "new."

The image Jesus creates is that of someone wealthy who presents the treasures of his household. Some of those items are old. We might think of antiques and family heirlooms. Some of the treasure is newly acquired, but still greatly valuable. Jesus pictures teachers of these great truths as those who show both God's revelation in the Old Testament Scriptures and the new revelations of God's truth through Jesus Christ. Those teachers would need to show how these treasured truths fit together.

This, in fact, is exactly what Matthew does in his gospel. He often references the "old treasures" of Israel's Scriptures to show how they are fulfilled in Jesus' work and words. The other men gathered before Jesus will do the same as they teach the gospel in the years to follow (2 Timothy 3:16; 1 John 1:1–4). That work will require them to understand Jesus' teaching in these parables.