Jesus has just finished teaching His series of parables on what the kingdom of heaven is like. Like any good teacher He asks His listeners, "Do you understand, have you got this?".
A scribe was an expert on the Law of Moses. By referring to a scribe who has become a disciple, Jesus places His imprimatur, His sanction on the law of the old testament. He implies that His teaching on God's kingdom is simply clarifying what has already been written.
The Church backs up the importance of the Law and the Prophets by having us hear them at Mass most days. Today is a classic from Exodus, describing how Moses built the tabernacle for the Arc of the Covenant. I'm tempted to say, "Who cares how the sockets of the tabernacle were joined?". Well, Jesus for one. Maybe it's the obedience of Moses to God's instructions that is the message here. As Saint Paul wrote...
All scripture is inspired by God and can profitably be used for teaching, for refuting error, for guiding people's lives and teaching them to be holy. This is how the man who is dedicated to God becomes fully equipped and ready for any good work.
2 Timothy 3:16,17
Lord Jesus, often I think I know it all. Forgive me and heal me of my pride. Help me to be teachable by Your Word, both new and old.
Little Flower, please pray for me.