This is indeed a translation that ultimately failed to express the meaning, but it is not likely that St. Jerome simply erred:
The depiction of a horned Moses stems from the description of Moses' face as "cornuta" ("horned") in the Latin Vulgate translation of the passage from Exodus in which Moses returns to the people after receiving the commandments for the second time.[10] The Douay-Rheims Bible translates the Vulgate as, "And when Moses came down from the mount Sinai, he held the two tables of the testimony, and he knew not that his face was horned from the conversation of the Lord."[11] This was Jerome's effort to faithfully translate the difficult, original Hebrew Masoretic text, which uses the term, karan (based on the root, keren, which often means "horn"); the term is now interpreted to mean "shining" or "emitting rays" (somewhat like a horn).[12][13] Although some historians believe that Jerome made an outright error,[14] Jerome himself appears to have seen keren as a metaphor for "glorified", based on other commentaries he wrote, including one on Ezekiel, where he wrote that Moses' face had "become 'glorified', or as it says in the Hebrew, 'horned'."[6]:77[9]:98–105 The Greek Septuagint, which Jerome also had available, translated the verse as "Moses knew not that the appearance of the skin of his face was glorified."[15] In general medieval theologians and scholars understood that Jerome had intended to express a glorification of Moses' face, by his use of the Latin word for "horned."[6]:74–90 The understanding that the original Hebrew was difficult and was not likely to literally mean "horns" persisted into and through the Renaissance.[16]
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