There are two ways to look at the offer given to Ammon. The first is that king Lamoni was so impressed with him and his commitment to dwell among the Lamanites that he wanted to honor him with the marriage of his daughter. The second is that the king's daughter was so beastly to look at, that there were no Lamanites in the entire kingdom that would have her hand in marriage. Under this interpretation, King Lamoni was trying to pawn off his homely daughter on the first Nephite he could find. The reader is left to choose which of these interpretations is correct, but the author favors the latter.