"Then shall the kingdom of heaven be like to ten virgins, who taking their lamps went out to meet the bridegroom and the bride. And five of them were foolish and five wise. But the five foolish, having taken their lamps, did not take oil with them. But the wise took oil in their vessels with the lamps. And the bridegroom tarrying, they all slumbered and slept. And at midnight there was a cry made: 'Behold the bridegroom cometh. Go ye forth to meet him.' Then all those virgins arose and trimmed their lamps. And the foolish said to the wise: 'Give us of your oil, for our lamps are gone out.' The wise answered, saying: 'Lest perhaps there be not enough for us and for you, go ye rather to them that sell and buy for yourselves.' Now whilst they went to buy the bridegroom came: and they that were ready went in with him to the marriage. And the door was shut. But at last came also the other virgins, saying: 'Lord, Lord, open to us.' But he answering said: 'Amen I say to you, I know you not.' Watch ye therefore, because you know not the day nor the hour."
WATCHFULNESS: Our Lord Himself points the moral of this parable by His concluding words: "Watch you, therefore, because you know not the day nor the hour (of your death)." We ought to live on the watch, and be always ready for the coming of our Divine Judge, because 1. we know not when we shall be called away; 2. the hour of death is, as a rule, too late for conversion and the gaining of merit; and it is therefore a mischievous act of carelessness to put off conversion till the hour of death.
[From 'A Practical Commentary on Holy Scripture' by Bishop Knecht, D.D.]
(1899 Douay-Rheims Bible)