Helaman collapses time in this recitation, and shows himself a poor storyteller. There is great drama in this little story, but Helaman does not exploit the tension that was there. This is because Helaman’s intent is to laud the faith and miraculous preservation of his band of Ammonites. For the modern reader, however, we could use an understanding of this dramatic situation.
Helaman makes the decision to send this unruly bunch of prisoners to Zarahemla. In order to do so he must send a fair number of men to guard them precisely because they had been so unruly. Thus Helaman’s entire army had been reduced not by attrition, but by the need to guard prisoners that they decided not to murder in the field. The net effect of the mission was to decrease Helaman’s effective fighting force.
Helaman would also have left some men to guard Cumeni, but appears to have been returning to Judea. In any event, as they are in the field the Lamanites fall upon them and they are on the verge of defeat. As they are facing defeat at the hands of the Lamanites they have a miraculous salvation. The force that had been sent with the prisoners returns and is able to swing the tide of the battle in favor of the Nephites.
The arrival of these reinforcements is miraculous to those who were fighting because they should not have been able to return. Zarahemla was further off, and they should not have been able to reach Zarahemla and return. Returning early should have meant that they still had the Lamanite prisoners with them, and the presence of those prisoners would make it more difficult for them to fight effectively. In spite of all of these reasons that they should not have been able to help, they were nevertheless there in time, and the battle was won. In the next few verses we learn why.