“The kingdom of heaven is like treasure, buried in a field, that a man found and reburied. Then in his joy he goes and sells everything he has and buys that field.
“Again, the kingdom of heaven is like a merchant in search of fine pearls. When he found one priceless pearl, he went and sold everything he had and bought it."
The two parables highlight the singular value and worth of the kingdom. Both also highlight the hiddenness of the kingdom. And finally, both parables highlight the "selling of everything" to secure the kingdom.
The hiddenness is most apparent in the Parable of the Hidden Treasure. The Hidden Treasure is, of course, hidden. There is something of great value which is being overlooked. Once discovered, however, the value motivates an absolute commitment to securing it. The man, with joy, sells everything he has to buy the field where the treasure is hidden. In the Parable of the Pearl of Great Price, the merchant is, like a treasure hunter, searching for fine pearls. And his search pays off when he finally discovers the find of a lifetime, a "priceless" (CSB translation) pearl. Finding this pearl, the merchant sells everything he has to buy it. The value of the pearl creates a singular consolation: Everything is exchanged for this one thing.
I've been describing the parables of Matthew 13 as pessimistic. Perhaps that isn't the best word. But I'm using it to point to things like the hidden aspect of the kingdom. No doubt the kingdom is of inestimable value, worth "selling everything" to obtain. Consequently, we like to highlight and advertise this value. If people knew the kingdom's worth they would come! And yet, in both of these parables the value of the kingdom isn't announced. The value is perceived only by a single person. Others don't know where the treasure is buried or cannot see the value of the pearl they are selling. Rather than being marketed and broadcast abroad, the value of the kingdom in these parables goes back to the issue of perception. The value has to be perceived. The parables highlight discovery (the treasure) and searching (the pearl). You have to be looking for it. Consequently, only a few will make the discovery.
Again, Jesus' audience is the interpretation of these parables. Jesus is offering a treasure, but it is hidden. He is setting before them a priceless pearl, and they are willing to give it away. Others, however, perceive the value and will "sell everything" to follow Jesus, will make the utmost commitment to secure the kingdom. The pessimistic note here, highlighted in these parables, is that those who reject the kingdom greatly outnumber those who accept it. They walk by the hidden treasure and see the pearl bought by another.