Gregory the Great, on Ezek 34:18

“Was it not enough for you to feed upon good pastures? but you must also tread down with your feet the residue of your pastures: and when you drank the dearest water, you troubled the rest with your feet.”

“For indeed the shepherds drink most pure water, when with a right understanding they imbibe the streams of truth. But to foul the same water with their feet is to corrupt the studies of holy meditation by evil living. And verily the sheep drink the water fouled by their feet, when any of those subject to them follow not the words which they hear, but only imitate the bad examples which they see. Thirsting for the things said, but perverted by the works observed, they take in mud with their draughts, as from polluted fountains.”

Imported from an open dataset — not yet checked against the printed edition.