What does Luke 2:19 mean?

When Mary was first approached by an angelic messenger, she responded with humility and submission to God (Luke 1:38). The angel told her how her Son would be the Messiah—including the great titles and accomplishments He would experience (Luke 1:30–33). After travelling to Bethlehem and giving birth, Mary is now surrounded by local shepherds and likely some other group of bystanders (Luke 2:1–18).

Here, as before, Mary reacts thoughtfully. We're not told exactly what she is thinking. She doesn't take the moment for granted, at least: she appreciates the importance of these events. As the shepherds explain their angelic encounter, she "treasures" and "ponders" what is happening. These ideas are expressed using the Greek root words suntereo and sumballo. The first implies protection and remembrance. The second implies preserving and observing. Mary makes a deliberate effort to remember all that she sees.