Korihor said unto him: ... ye do not know that there is a God; and except ye show me a sign, I will not believe.

Now Alma said unto him: This will I give unto thee for a sign, that thou shalt be struck dumb. ...

Now when Alma had said these words, Korihor was struck dumb. Alma 30:48

Korihor said unto him: ... ye do not know that there is a God; and except ye show me a sign, I will not believe. Now Alma said unto him: This will I give unto thee for a sign, that thou shalt be struck dumb. ... Now when Alma had said these words, Korihor was struck dumb. Alma 30:48