The Most Ancient Lives of Saint Patrick/The Life and Acts of St. Patrick/Chapter 66
Of the two Rivers, Dubh and Drobhaois.
In that country were two rivers, whereof the one was called Dubh, and the other Drobhaois; and the river Dubh was wont to abound with fishes, but the other produced them not. And the saint, passing nigh the bank of the fruitful river, entreated the fishermen that out of a great draught which they had taken they would bestow their kindness unto him. But they, wanting charity toward the beloved of the Lord, sent him away empty, and wholly refused unto him even one fish. Therefore God, the author and the lover of charity, from these fishermen, narrowed in their hearts, and frozen with covetousness, withdrew their wonted gain, and deprived that river of its perpetual abundance of fishes; and the other river, which was called Drobhaois, did he immediately enrich therewith. And this river, as being more fruitful, so is it clearer than all the other rivers in Ireland. From whence a wise man may understand that we should show charity unto every member of Christ, and receive the friends of God and relieve them with all kindness. For whatever honor, whatever kindness, we show unto them, that do we assuredly show unto Christ; so whatever we unjustly take from or deny unto them, of that doth God attest us to have defrauded Him.