After having defeated the Lamanite army in the previous chapter, Moroni, the leader of the Nephite army, lays out some terms to Zerahemnah, the leader of the Lamanite army, in Alma 44. Moroni offers to spare the lives of the remaining Lamanite soldiers if they surrender their weapons of war, leave the Nephite land, and promise to never return to war against the Nephites again.
Zerahemnah readily agrees to the first two points. He tells Moroni, "take our weapons of war, and suffer that we may depart into the wilderness" (verse 8). However, he is not willing to make the promise to never return for another war, telling Moroni, "we will not…take an oath unto you, which we know that we shall break" (verse 8).
Let's give Zerahemnah a little credit for honesty here. The easy thing to do would be to say whatever he is asked to say at the time and then do whatever he wants to do later. Instead, he takes the position that he will only make a promise if he intends to keep it.