MATTHEW 13 44 “Again, the kingdom of heaven is like treasure hidden in a field, which a man found and hid; and for joy over it he goes and sells all that he has and buys that field.45 “Again, the kingdom of heaven is like a merchant seeking beautiful pearls, 46 who, when he had found one pearl of great price, went and sold all that he had and bought it.47 “Again, the kingdom of heaven is like a dragnet that was cast into the sea and gathered some of every kind, 48 which, when it was full, they drew to shore; and they sat down and gathered the good into vessels, but threw the bad away. 49 So it will be at the end of the age. The angels will come forth, separate the wicked from among the just, 50 and cast them into the furnace of fire. There will be wailing and gnashing of teeth.” 51 Jesus said to them, “Have you understood all these things?” They said to Him, “Yes, Lord.” 52 Then He said to them, “Therefore every scribe instructed concerning the kingdom of heaven is like a householder who brings out of his treasure things new and old.”

Through the comparison of a treasure in the field of our hope, Christ points to wealth that has been covered up, for God is discovered in humanity…But an explanation is needed here as to both the matter concerned and what was said. Thus the treasure was hidden because it was necessary to buy the field. The treasure in the field, as we said, signifies Christ in the flesh, who was found freely. Indeed, the preaching of the Gospels has no strings attached, but the power to use and own this treasure with the field comes at a price, for heavenly riches are not possessed without a worldly loss.
(St. Hilary)