Jamieson, Fausset and Brown on Matthew 13:44

44. Again, the kingdom of heaven is like unto treasure hid in a field--no uncommon thing in unsettled and half-civilized countries, even now as well as in ancient times, when there was no other way of securing it from the rapacity of neighbors or marauders. (Jr 41:8; Job 3:21; Pr 2:4).

the which when a man hath found--that is, unexpectedly found.

he hideth, and for joy thereof--on perceiving what a treasure he had lighted on, surpassing the worth of all he possessed.

goeth and selleth all that he hath, and buyeth that field--in which case, by Jewish law, the treasure would become his own.

The Pearl of Great Price (Mt 13:45, 46).