Zerahemnah was given a chance to swear an oath, and he responded, “Behold, here are our weapons of war; we will deliver them up unto you, but we will not suffer ourselves to take an oath unto you, which we know that we shall break, and also our children.”
Captain Moroni’s terms included the following conditional: “if ye will go your way and come not again to war against us” (Alma 44:6). To Zerahemnah, that meant, “You will not come again, and you will not have your children come either.” He counteroffered, “Take our weapons of war and suffer that we may depart into the wilderness.” In other words: “Just let us go. You can have our weapons, but we are not going to swear this oath.” But Moroni refused.
Why would Zerahemnah rather risk losing his head than swear that oath? That is all he needed to do, and Moroni would have let him go free. Why would he not do that? He knew that neither he nor his posterity would keep it, but so what? Would someone today worry about that? It goes back to how they viewed oaths in the ancient world as binding commitments enforceable by God, and he was not prepared to deal with the consequences of breaking the oath.
Book of Mormon Central, “Why Would Zerahemnah Not Swear an Oath to Moroni? (Alma 44:8),” KnoWhy 152, (July 27, 2016). “The elements of Alma 44 combine to show that both the Nephites and Lamanites, including even the wrathful Zerahemnah, respected the seriousness of oaths, especially oaths sworn in God’s name. This in turn demonstrates the rich complexity of the Book of Mormon as well as it supports its ancient provenance.”