Thomas of Cantimpré [circa 1200-1272 CE] (Liber de natura rerum, Quadrupeds 4.40): They say that the ermine is a small animal of the genus weasel, but in shape it is smaller and the color is different. In the winter season it glows like snow, except at the tip of the tail. In summer, however, the belly only glows, but the back appears brown. It chases mice; it feeds on meat. The skins of these animals are of great interest to men, and are usually used in clothing. - [Badke translation/paraphrase]

Fiore di virtù [14th century] (Chapter XXXV): The virtue of moderation may be compared to the ermine who is the most moderate and most courteous and noblest animal in the world. Because of his great moderation and natural nobility he never eats more than once a day and would never touch any bad food. When it rains he never leaves his lair so as not to soil himself with mud. He does this because of his nobility. He never lives in a damp place but always chooses a dry spot. When hunters want to capture him they surround his lair with mud and as the ermine comes out, they immediately shut the entrance to his lair to keep him from going back. As he sees the hunters he flees. But coming to the mud, he lets himself be captured rather than smear his mantle. Such is his nobility. - [Fersen & Rosenwald translation]