"They seemed to have flung away all the golden grain of practical wisdom, which they had enjoyed so many opportunities of harvesting"
Minerva, the Roman goddess of wisdom (c.1539)
Public DomainMinerva, the Roman goddess of wisdom (c.1539) - Credit: Parmigianino

This is a reference to a parable that appears in the Book of John. When Jesus’ disciples, concerned that he is not eating, urge him to get some nourishment, he replies that he has his own means of sustenance of which they are unaware. “Say not ye, There are yet four months, and then cometh harvest? behold, I say unto you, Lift up your eyes, and look on the fields; for they are white already to harvest” (John 4:35). A harvest of grain takes four months to grow from seed; the harvest to which Christ refers is the wisdom of God which can be enjoyed immediately by those who are receptive to it.

Golden grain ready for harvest
Creative Commons AttributionGolden grain ready for harvest - Credit: Charles Knowles