What is the origin of this almost comical notion of Jews having horns? It is generally understood that the source of this idea is a mistranslation that occurred in the 4th century when St. Jerome translated the Bible into Latin (known as the Vulgate). The Vulgate, which became the accepted translation of the Catholic Church, translated the word of karan as horn. Moved the last sentence below
The mistranslation is based on a verse in Exodus that describes Moses after he descended from Mount Sinai where he received the Torah from God directly. “...and Moses did not know that his face shone with light when He [God] spoke with him” (Exodus 34:29). The Hebrew word for the light shining (karan) is basically the same as the word for horn (keren). They share the root letters kuf-reish-nun.
It was this translation that is the source of the strange horns attached to Michelangelo’s famous sculpture of Moses, furthering the absurd notion that Jews have horns.
Even though this mistranslation was acknowledged, the damage was already done and anti-Semites had yet one more slur to make against the Children of Israel.