Gregory the Dialogist

For by oil the splendor of glory is signified; and our vessels are our hearts, in which we carry all that we think. The wise therefore have oil in their vessels, because they retain the splendor of glory within their conscience, as Paul attests when he says: "Our glory is this, the testimony of our conscience." But the foolish virgins do not take oil with them, because they do not have glory within their conscience, since they seek it from the lips of their neighbors. …

Forty Gospel Homilies, Homily 12 ↗