Moses is depicted with horns, as opposed to "the radiance of the Lord", due to the similarity in the Latin between the word for "beams of light" and "horns". This kind of iconographoic symbolism was common in early sacred art, and in this case gives ease to the sculptor (as sculpting concrete horns is easier than sculpting abstract light) and would have been understood by all who saw it as referring to the radience of Moses' face; they would not have actually thought that he had horns.