Matthew 13:44

We have four short parables in these verses. I. That of the treasure hid in the field. Hitherto he had compared the kingdom of heaven to small things, because its beginning was small; but, lest any should thence take occasion to think meanly of it, in this parable and the next he represents it as of great value in itself, and of great advantage to those who embrace it, and are willing to come up to its terms; it is here likened to a treasure hid in the field, which, if we will, we may make our own. 1. Jesus Christ is the true Treasure; in him there is an abundance of all that which is rich and useful, and will be a portion for us: all fulness (Col 1:19; Joh 1:16): treasures of wisdom and knowledge (Col 2:3), of righteousness, grace, and peace; these are laid up for us in Christ; and, if we have an interest in him, it is all our own. 2. The gospel is the field in which this treasure is hid: it is hid in the word of the gospel, both the Old Testament and the New Testament gospel. In gospel ordinances it is hid as the milk in the breast, the marrow in the bone, the manna in the dew, the water in the well (Isa 12:3), the honey in the honey-comb.

— Matthew Henry's Concise Commentary (public domain)

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. (Jer 41:8; Job 3:21; Pro 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 (Mat 13:45-46).

— Jamieson-Fausset-Brown Commentary (public domain)