2 Nephi 14

And now behold, my beloved brethren, I suppose that ye ponder somewhat in your hearts concerning that which ye should do after ye have entered in by the way. But behold, why do ye ponder these things in your hearts? Do ye not remember that I said unto you that after ye had received the holy ghost, ye could speak with the tongue of angels? And now, how could ye speak with the tongue of angels save it were by the holy ghost? Angels speak by the power of the holy ghost; wherefore, they speak the words of Christ.