What does the expression “a wolf in sheep’s clothing” mean and Where does it come from?

Young people of today think they are very up to date when they refer to a carnally minded man, young or old, as a “wolf,” but the fact is that they are, roughly speaking, some twenty-five hundred years behind the times.

So anciently were such men known that Aesop, who lived in Greece about 600 B.C., told a fable about them.

He likened them to a wolf who got admission into a sheepfold by wrapping himself in the skin and fleece of a sheep. Thus, under the pretense that he was an innocent and harmless as a sheep, he was able to seize and devour unsuspecting young lambs that took his fancy.

The fables of Aesop were so familiar in Greece and the countries with which she enjoyed commerce that, possibly, this fable may have been the source of the passage in Matthew vii, 15: “Beware of false prophets, which come to you in sheep’s clothing, but inwardly they are ravening wolves.”

Or, perhaps, today’s ravening “wolf” got his name from the biblical passage, rather than directly from the fable, though no one can be certain.