The name that is transliterated as “Moses” in English is signed in Spanish Sign Language in accordance with the depiction of Moses in the famous statue by Michelangelo (see here ). (Source: John Elwode in The Bible Translator 2008, p. 78ff.)
“Moses” in Spanish Sign Language (source )
In French Sign Language, a similar sign is used, but it is interpreted as “radiance” (see below) and it culminates in a sign for “10,” signifying the 10 commandments:
“Moses” in French Sign Language (source )
The horns that are visible in Michelangelo’s statue are based on a passage in the Latin Vulgate translation (and many Catholic Bible translations that were translated through the 1950ies with that version as the source text). Jerome, the translator, had worked from a Hebrew text without the niqquds, the diacritical marks that signify the vowels in Hebrew and had interpreted the term קרו (k-r-n) in Exodus 34:29 as קֶ֫רֶן — keren “horned,” rather than קָרַו — karan “radiance” (describing the radiance of Moses’ head as he descends from Mount Sinai).
Even at the time of his translation, Jerome likely was not the only one making that decision as this recent article alludes to.