The story behind this soldier's predicament is even more astonishing. Why was this man so important, and who put him in danger?
This whole scenario is a setup orchestrated by the prophet. Earlier in 1 Kings 20, a prophet tells Ahab that he will win a great victory. After the battle, God brings this situation about to teach Ahab a lesson. The commanded penalty of life for life or a talent of silver was meant to mirror the penalty God would impose on Ahab if he let a specific enemy king (Ben-Hadad) go free.
Ahab, who had previously spared King Ben-Hadad of Syria against God's command, is being shown the very real consequences of his disobedience through this soldier's tale.