Alma 18:16 - 18:20
Alma 18:16 And it came to pass that Ammon, being filled with the Spirit of God, therefore he perceived the thoughts of the king. And he said unto him: Is it because thou hast heard that I defended thy servants and thy flocks, and slew seven of their brethren with the sling and with the sword, and smote off the arms of others, in order to defend thy flocks and thy servants; behold, is it this that causeth thy marvelings?
Ammon, while waiting for the Lamoni to say something, perceived that the king was almost afraid to speak to Ammon because of the account by the other servants of his beating off of the bad guys at the waters of Sebus and killing seven of them with his sling and his sword and cutting off of the arms of several others. Anyway, Ammon asks the king if this is why he is afraid to speak to Ammon.
Alma 18:17 I say unto you, what is it, that thy marvelings are so great? Behold, I am a man, and am thy servant; therefore, whatsoever thou desirest which is right, that will I do.
Ammon says to the king that his astonishment at his prowess is not to be marveled at so much. He is but a man and his servant. He will do whatever the kings asks him to do.
Alma 18:18 Now when the king had heard these words, he marveled again, for he beheld that Ammon could discern his thoughts; but notwithstanding this, king Lamoni did open his mouth, and said unto him: Who art thou? Art thou that Great Spirit, who knows all things?
The king was taken back again. He now knew that Ammon could read his mind as well. But the king got up enough courage to ask Ammon if he was the Great Spirit? The Great Spirit that knew everything that was going to happen.
Alma 18:19 Ammon answered and said unto him: I am not.
Ammon replied that he was not the Great Spirit.
Alma 18:20 And the king said: How knowest thou the thoughts of my heart? Thou mayest speak boldly, and tell me concerning these things; and also tell me by what power ye slew and smote off the arms of my brethren that scattered my flocks—
The king now gives Ammon permission for him speak without fear. Lamoni wants to know by what power he was able to kill so many of the bad guys who had tried to scatter his flocks.