6 Lo, unto the comprehending of what are we being nourished up; lo, unto the embracing and the feeding on what are we being nourished up; yet so as that that which is fed on is not diminished, and he that feeds is supported. For now food supports us by eating it; but the food which is eaten, is diminished; but when we shall begin to feed on Righteousness, to feed on Wisdom, to feed on that Food Immortal, we are at once supported, and That Food is not diminished. For if the eye knows how to feed on light, and yet does not diminish the light; for the light will be no less because it is seen by more; it feeds the eyes of more, and yet is as great as it was before: both they are fed, and it is not diminished; if God has granted this to the light which He has made for the eyes of the flesh, what is He Himself, the Light for the eyes of the heart? If then any choice food were praised to you, on which you were to dine, you would prepare the stomach; God is praised to you, prepare the heart.
Source: Sermons on Selected Lessons of the New Testament (New Advent)