Exodus 34:29-35, according to most translations, tells that after meeting with God the skin of Moses' face became radiant, frightening the Israelites and leading Moses to wear a veil. Jonathan Kirsch, in his book Moses: A Life, thought that, since Moses subsequently had to wear a veil to hide it, Moses' face was disfigured by a sort of "divine radiation burn".

This Exodus passage has led to one longstanding tradition that Moses grew horns. This is derived from an alternative interpretation of the Hebrew phrase qâran ‘ôr pânâw (קָרַן עוֹר פָּנָיו). The root קרן Q-R-N (qoph, resh, nun) may be read as either "horn" or "ray of light", depending on context. As a noun, this word turns up some ninety times within the Hebrew Bible, and always means "horn". The alternative meaning, "ray of light", turns up only in the post-Biblical Hebrew literature. As a verb, the three verses describing Moses' appearance are the only three examples in the Biblical and post-Biblical literature of this verb ever being translated as "shine". Aside from the references to Moses, the verb is always understood to mean "have horns" (cf: Ps 69:32, for the one other Biblical occurrence). ‘ôr pânâw (עוֹר פָּנָיו) translates to "the skin of his face".[125]