"In the Savior’s parable of the ten virgins, each young woman had a lamp. Clearly, this parable has both a temporal and a spiritual application. Oil can be purchased at the market. But another kind of oil, spiritual oil that is not for sale, can be accumulated only by our daily good works.
The parable tells what happened as all ten young women waited for the bridegroom. The bridegroom came at the darkest hour, when least expected. It was midnight, and the foolish five had run out of oil. You might wonder why the five wise virgins could not share their oil with the other five. It was not selfishness on their part. Spiritual preparedness cannot be shared in an instant because we each fill our lamps drop by drop in our daily living." - President Faust
Spencer W. Kimball defined those drops of oil for us when he said:
“There are oils that keep the gospel burning brightly. One type of oil is the oil of family prayer. It illuminates us and makes us bright and cheery but is difficult to obtain at midnight. One drop or two will not keep the lamp burning long.
“Another type of oil is the oil of fasting. The last midnight is late to start disciplining our lives in preparation for the great day of the Lord. …
“Another oil that is not available at midnight is the indispensable oil of home service. This rare oil of service is accumulated through visits to the sick, through lending a helping hand. …
“There is another oil that all will need—rich or poor, sick or well. Its light is brilliant and increases with use. The more that is used, the more that is left. It is easy to purchase in the day but not available at night. This is the tithing oil."