Ante-Nicene Fathers, Vol IX:
Origen's Commentary on the Gospel of Matthew.: Chapter V

5.  The Field and the Treasure Interpreted.

And here we must inquire separately as to the field, and separately as to the treasure hidden in it, and in what way the man who has found this hidden treasure goes away with joy and sells all that he has in order to buy that field; and we must also inquire—what are the things which he sells.  The field, indeed, seems to me according to these things to be the Scripture, which was planted with what is manifest in the words of the history, and the law, and the prophets, and the rest of the thoughts; for great and varied is the planting of the words in the whole Scripture; but the treasure hidden in the field is the thoughts concealed and lying under that which is manifest, “of wisdom hidden in a mystery,” “even Christ, in whom are all the treasures of wisdom and knowledge hidden.” 5185   But another might say that the field is that which is verily full, which the Lord blessed, the Christ of God; but the treasure hidden in it is the things said to have been “hidden in Christ” by Paul, who says about Christ, “in whom are the treasures of wisdom and knowledge hidden.”  The heavenly things, therefore, even the kingdom of heaven, as in a figure it is written in the Scriptures—which are the kingdom of heaven, or Christ—Himself the king of the ages, are the kingdom of heaven which is likened to a treasure hidden in the field.

Footnotes

Col. ii. 3.