Here Mormon, who was the abridger of this record, adds one of his frequent observations in explanation of data recorded. He now interpolates the information, evidently to impress us with the fact, that the Lord's promise to Ammon's father, King Mosiah, was not forgotten in the maze of quickly occurring events, and that because of that promise Ammon could not be slain. That promise is again revealed to us in Mormon's reference to Mosiah's faith.
You will remember that to the appeals of his sons that they might be permitted to go on missions to the savage Lamanites, Mosiah was at first greatly opposed. He knew the bloodthirsty character the Lamanites had inherited from their forefathers, and what were the beliefs of the dark-skinned sons and daughters of Laman. He supposed, also, that little or no good would come from what he thought was such an ill-advised venture. But to his sons' earnest desire he wanted to place no obstacle in their way that might discourage their holy resolution. Mosiah inquired of the Lord. He wanted to know what course to pursue in this ever-increasingly, pertinent matter.
The answer came from the Lord, "Let them go up." (Mosiah 28:7) And Mormon further records other words of the Lord concerning Mosiah's request: " 'I will spare him [Ammon], and it shall be unto him according to thy faith,' therefore, Mosiah trusted him unto the Lord."
Let us remember in contemplating this wondrous story that no one ever perished who trusted in the Lord.