Two victories over the Lamanites in the land of Desolation gave the Nephites a false sense of power and security. Again, they failed to recognize that it was the Lord who was the real source of both. Mormon refused to add to their self-deception by continuing to be their leader. Without a prophet-commander, the people violated the Lord’s principle of defensive warfare (D&C 98:33–48) and sought to avenge the blood of their brethren and comrades by initiating an attack on their enemy. Furthermore, the Nephites swore oaths by heaven, the very thing the Lord had forbidden during his sermon at the temple in Bountiful (3 Nephi 12:34) and in the Sermon on the Mount in the Old World (Matthew 5:34).