Here’s an interesting article about a book on visiting illuminated manuscripts. Hopefully the content doesn’t reflect the book.
Moses is described as “horned” throughout the Middle Ages, and of course Michelangelo’s famous statue shows Moses with horns. This was not because people thought Jews had horns.
(Obviously an idea that couldn’t survive any city where Jews lived. Jews got their hats knocked off a lot; it was a common harassment thing. However, it is true that people in the waybacks always seem to tell kids that various minority ethnic or religious groups who don’t live around them have tails and horns, like the Russian eretik monsters. You sometimes hear people on the Internet who say that their grandparents were taught that about Catholics.)
The reason Moses was called “horned” was because the Vulgate said the same thing. This was how St. Jerome, who studied Hebrew with Jews, translated Exodus 34:35:
“Qui videbant faciem egredientis Moysi esse cornutam, sed operiebat ille rursus faciem suam, siquando loquebatur ad eos.”
“Upon Moses coming out, they saw his face was horned, but he covered his face back up whenever he spoke to them.”
The usual English translation these days is that “the skin of Moses’ face shone.” So what people think is, “How dumb St. Jerome was! What a terrible translation error!”
But the Hebrew word used in this passage for “shine” is “karan,” which literally means “horn.”
As this gentleman Taylor Marshall explains, the Hebrew idea was that a ray of light was shaped like a horn. Horns were also symbols of power, as we see again and again in the Books of Daniel and Revelation. So after seeing God, Moses suddenly had some kind of frightening light of power coming out from his head. Horns.
Mr. Marshall also points out that Hebrew altars had horns, and altars were veiled. He suggests that the wording means that Moses was now a living altar of God.