From Faith Futures
The brief commentary in [The Five Gospels] (p. 197) concludes with these observations:
The pearl is a common symbol for something precious, sometimes for a special kind of wisdom: "Don't throw your pearls to dogs, or they'll trample them underfoot." (Matt 7:6). In this parable, the merchant invests all he has in the one pearl. What good will that do him? None at all, unless the pearl stands for something more valuable than all his capital. That is a provocative way of illusrtating the challenge of God's imperial rule.