Why did Michelangelo Buonarroti depict the biblical figure Moses with horns on his head?

The Moses is a sculpture by the Italian High Renaissance artist Michelangelo Buonarroti, housed in the church of San Pietro in Vincoli in Rome. Commissioned in 1505 by Pope Julius II for his tomb, it depicts the biblical figure Moses with horns on his head.

The depiction of a horned Moses stems from the description of Moses' face as "cornuta" ("horned") in the Latin "Vulgate" translation of the passage found at "Exodus" chapter 34, specifically verses 29, 30 and 35, in which Moses returns to the people after receiving the commandments for the second time.

The 4th century translation was done by St.Jerome from a very difficult, original Hebrew Masoretic text. The term "קָרַ֛ן‬, qāran" (based on the root, "קָ֫רֶן‬ qeren") often means "horn"; but at the same time may be interpreted as "shining" or "emitting rays".

The Douay-Rheims Bible (1582) 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."

Contemporary translation in the New King James Version (1982) is as follows: "Now it was so, when Moses came down from Mount Sinai (and the two tablets of the Testimony were in Moses’ hand when he came down from the mountain), that Moses did not know that the skin of his face shone while he talked with Him."