Once again we have one of the Parables of the Kingdom (as Robert Capon categorizes it). And once again what seems like a simple obvious statement isn't really that simple and obvious.
What is the Kingdom of Heaven in this story? Is it the pearl? Is it the merchant searching for pearls--the process of trying to find? Is it the committing to one thing rather than many things? Is it the extent of the commitment to that one thing--he "sold all that he had" to buy it?
The two main foci would seem to be the pearl and the merchant. In those times, a "merchant" was not seen as the respectable entrepreneur who keeps the economy of the society humming along. Throughout the Bible, the word translated "merchant" here usually refers to someone much more disreputable--for example, in Genesis, when Joseph (of the coat of many colors) was sold into slavery by his brothers, it was "merchants" who bought him. A "merchant" is more likely to cheat you out of your money in some sort of scam than to sell you something of value. Those Jesus cleared out of the Temple were "merchants"--and Jesus was very skeptical of their integrity; even as they performed a necessary function they were likely exploiting those whom they were selling to, that "captive audience" (in more ways than one) who basically had no other options. So this guy isn't someone who would usually be the hero of a story (neither was the "Good Samaritan," so we can see that Jesus has a tendency both to challenge stereotypes and to call out depths of redemption as he practiced it).
And the "pearl"--most of the people whom Jesus is telling this story to would never have even seen a pearl, much less owned one. Pearls were the most precious jewel anyone could have, and were much too expensive for those in the socioeconomic status of Jesus and the other poor people of Israel, crushed under Roman rule. So this would be a very compelling story for Jesus to tell, and would get them thinking about things valued beyond the range of their lives' possibilities. Wow--what would I do to get this something that I don't have any possible chance of every having? Questions for us too.
The story itself hits them--and then to say that the Kingdom of Heaven is like this? What could that possibly mean?
GOSPEL Matthew 13:45-46
45‘Again, the kingdom of heaven is like a merchant in search of fine pearls; 46on finding one pearl of great value, he went and sold all that he had and bought it.