The hard hearts of the Nephites, which had become like stone, rejected Mormon's appeals, and unmindful of His help, refused to admit they conquered in the strength of the Lord, but boasted in their own might. Day by day they went their way forgetting His wisdom and guidance. They forgot that their utmost strength when compared to God's was absolute weakness, and their wisdom but foolishness. They had no alliance with a power greater than theirs. In their folly this they would not recognize, but swore "before the Heavens that they would avenge themselves of the blood of their brethren." Not only that, but they called upon God to witness their determination to cut their enemies "off from the face of the land."
For them to rely upon their own impregnability and ignore His might was repugnant to the Lord's purposes as proclaimed by Mormon. The wickedness and abandonment of the Nephite people were fast reaching their maximum. They sought not the Lord, but repelled His Spirit and knowingly rebelled against His mandates. For this reason, and this reason alone, Mormon refused to longer be their Commander. Here Mormon recalls that in spite of their waywardness, he had led the Nephites many times into battle, and had done so because they were his people, and therefore he had loved them with a fervor almost divine. And in this love he had unceasingly poured out his heart in prayer unto God that He in His might would save them from their own folly. But, Mormon sadly notes that because "of the hardness of their hearts" his petitions did not prevail before Him Who reigns On High. Notwithstanding the fact of which they were aware, that in recent years Mormon had led the Nephite Armies to victory when the Nephites were attacked by the Lamanites, the people nevertheless did not repent of their wickedness. They continued on in their iniquity, and in their unhallowed wrath swore by the Heavens and by the Throne of God in what they thought was their newly found strength that they would persist in battle until the blood of their brethren who had been slain in previous encounters was avenged.
This was not pleasing unto the Lord Who had commanded that man should not swear by anything. And inasmuch as all thoughts of God had been crowded from their hearts, and no praise or thanksgiving offered Him by the Nephites for their deliverance, His voice came to Mormon: "Vengeance is Mine, and I will repay." It was not for the Nephites to mete out punishment, or to inflict it for past injuries or offenses committed by the Lamanites as the Nephites had sworn to do, but to leave it to God in Heaven Who knoweth the end from the beginning. Evidently, the Lord had become weary of the Nephites' sinful ways,) I am weary with repenting, many times the Lord had thought to destroy the wicked Jews, and just as many times had relented because of the prayers of the righteous, but now their cup of iniquity was full and He refused to alter His decision to destroy them. He would not again change the verdict He had given. Also read Mormon 5:1 where the word repent is used in exactly the same sense.
The great purpose for which Mormon addressed his exhortation was that all men must "stand before the Judgment-Seat of Christ ... to be judged of your works, whether they be good or evil." (v. 20) To the end that no one shall have an excuse for his actions and thereby be prepared when that time comes, Mormon, with sincere purpose of heart, closes his warning with a prayer: "I would that I could persuade all ye ends of the earth to repent and prepare to stand before the Judgment-Seat of Christ."1 and now His long-suffering was at an end, He said: "They shall be cut off from the face of the earth."