Jerome
Catena Aurea · Matthäusevangelium 25
Then shall the kingdom of heaven be likened unto ten virgins, which took their lamps, and went forth to meet the bridegroom. And five of them were wise, and five were foolish. They that were foolish took their lamps, and took no oil with them: But the wise took oil in their vessels with their lamps. While the bridegroom tarried, they all slumbered and slept. And at midnight there was a cry made, Behold, the bridegroom cometh; go ye out to meet him. Then all those virgins arose, and trimmed their lamps. And the foolish said unto the wise, Give us of your oil; for our lamps are gone out. But the wise answered saying, Not so; lest there be not enough for us and you: but go ye rather to them that sell, and buy for yourselves. And while they went to buy, the bridegroom came; and they that were ready went in with him to the marriage: and the door was shut. Afterward came also the other virgins, saying, Lord, Lord, open to us. But he answered and said, Verily I say unto you, I know you not. Watch therefore, for ye know neither the day nor the hour wherein the Son of man cometh.
For the Lord knoweth them that are his, (2 Tim. 2:19.) and he that knoweth not shall not be known, and though they be virgins in purity of body, or in confession of the true faith, yet forasmuch as they have no oil, they are unknown by the bridegroom. When He adds, Watch therefore, because ye know not the day nor the hour, He means that all that has been said points to this, namely, that seeing we know not the day of judgment, we should be careful in providing the light of good works.