Ambrose of Milan

The holy movements of our senses, which are according to virtues, themselves are the firstfruits of a spiritual ark: therefore they are likened to a rural ark, in which the corn is winnowed. For just as wheat and barley are separated from the chaff when threshed in this rural area and, as they are repeatedly winnowed, the chaff and other impurities of the harvest are scattered by the gentle breath of the air in different directions, but those which are more solid fall back into the same place after the dust is shaken out, so the …

On Cain and Abel ↗