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

10.  The Pearl of the Gospel in Relation to the Old Testament.

“To everything then is its season, and a time for everything under heaven,” 5204 a time to gather the goodly pearls, and a time after their gathering to find the one precious pearl, when it is fitting for a man to go away and sell all that he has in order that he may buy that pearl.  For as every man who is going to be wise in the words of truth must first be taught the rudiments, and further pass through the elementary instruction, and p. 419 appreciate it highly but not abide in it, as one who, having honoured it at the beginning but passed over towards perfection, is grateful for the introduction because it was useful at the first; so the perfect apprehension of the law and the prophets is an elementary discipline for the perfect apprehension of the Gospel, and all the meaning in the words and deeds of Christ.

Footnotes

Eccles. iii. 1.