Ammon understands what Lamoni is undergoing, because he has seen his friend, Alma, undergo a similar process. This was a process of dramatic conversion, where a lifetime of beliefs and experiences and understandings had to be reversed and replaced with the knowledge of the gospel. The message of the coming Messiah was that repentance was possible, but being possible does not mean that it was simple or painless. The imagery of the king lying as though dead is one who is to be raised to a new life. While that symbolism would be immediately recognized by modern Christians as echoing the death and resurrection of Christ and the symbolism of baptism, we do not see that explanation applied in this case. The reason is that Christ has not yet come, and the reality of this death and resurrection was never the New World symbol that it became after his resurrection in the Old World.
The important statement from Ammon to the queen is “he is not dead, but sleepeth in God.” Lamoni would rise, and God’s hand would be revealed.