Ambrose of Milan
Patristic
A.D. 339–397
“But what shall I say about the dogs, to whom it is ingrained by a certain nature to show gratitude and pretend anxious guard for the safety of their masters? Hence Scripture cries out against those ungrateful for kindness and lazy and idle: 'Dumb dogs, who cannot bark' (Isaiah 56:10). So there are dogs who know how to bark for their masters, who know how to defend their own dwelling places. Therefore, you too learn to raise your voice for Christ, when heavy wolves invade the sheepfold of the Church. Learn to hold the word in your mouth, so that you do not seem to have abandoned the custody of faith like a mute dog with the silence of transgression. Such a dog is a traveler and companion of angels, whom Raphael in the prophetic book thought it was not without purpose to join to himself and to the son of Tobias, when he went to chase away Asmodaeus and to strengthen the conjugal bond (Tob. VI, 1, and XI, 9). For with the grace of a mindful affection, the demon is driven away and the marriage is established. The holy angel Raphael, in the guise of a mute beast, instructed the young Tobias, whom he had taken upon himself to protect, about the experience of grace. For who would not be ashamed not to repay gratitude to those who deserve it well, when even beasts are seen to shun the crime of ingratitude? And those animals preserve the memory of the bestowed nourishment, do you not preserve the memory of the received salvation?”