The Itinerary of Archbishop Baldwin through Wales by Giraldus Cambrensis (J. M. Dent edition, 1912), tells how William de Braose's deception of the church was revealed:
I have determined not to omit mentioning those occurrences worthy of note which happened in these parts in our days. It came to pass before that great war, in which nearly all this province was destroyed by the sons of Jestin, that the large lake, and the river Leveni, which flows from it into the Wye, opposite Glasbyry, were tinged with a deep green colour. The old people of the country were consulted, and answered, that a short time before the great desolation caused by Howel, son of Meredyth, the water had been coloured in a similar manner.
About the same time, a chaplain, whose name was Hugo, being engaged to officiate at the chapel of Saint Nicholas, in the castle of Aberhodni, saw in a dream a venerable man standing near him, and saying, "Tell thy lord William de Braose, who has the audacity to retain the property granted to the chapel of Saint Nicholas for charitable uses, these words: "The public treasury takes away that which Christ does not receive; and thou wilt then give to an impious soldier, what thou wilt not give to a priest.'" This vision having been repeated three times, he went to the archdeacon of the place, at Landeu, and related to him what had happened.
The archdeacon immediately knew them to be the words of Augustine; and shewing him that part of his writings where they were found, explained to him the case to which they applied. He reproaches persons who held back tithes and other ecclesiastical dues; and what he there threatens, certainly in a short time befell this withholder of them: for in our time we have duly and undoubtedly seen, that princes who have usurped ecclesiastical benefices (and particularly king Henry the Second, who laboured under this vice more than others), have profusely squandered the treasures of the church, and given away to hired soldiers what in justice should have been given only to priests.