Helaman 13:2-5

2And it came to pass that in this year there was one Samuel, a Lamanite, came into the land of Zarahemla, and began to preach unto the people. And it came to pass that he did preach, many days, repentance unto the people, and they did cast him out, and he was about to return to his own land.

3But behold, the voice of the Lord came unto him, that he should return again, and prophesy unto the people whatsoever things should come into his heart.

4And it came to pass that they would not suffer that he should enter into the city; therefore he went and got upon the wall thereof, and stretched forth his hand and cried with a loud voice, and prophesied unto the people whatsoever things the Lord put into his heart.

5And he said unto them: Behold, I, Samuel, a Lamanite, do speak the words of the Lord which he doth put into my heart; and behold he hath put it into my heart to say unto this people that the sword of justice hangeth over this people; and four hundred years pass not away save the sword of justice falleth upon this people.