Origen

Otherwise; Notwithstanding they were foolish, they yet understood that they must have light to go and meet the bridegroom, that all the lights of their senses might be burning. This also they discerned, that because they had little of the spiritual oil, their lamps would burn dim as darkness drew on. But the wise send the foolish to those that sell, seeing that they had not stored up so much oil, that is, word of doctrine, as would suffice both for themselves to live by, and to teach others, Go ye rather to them that sell, i. e. to the doctors, and buy, i. e. take of them; the price is perseverance, the love of learning, industry, and toil of all who are willing to learn.