Takethemalive - He was confident of victory. Do not slay them; bring them to me, they may give us some useful information.
Matthew Henry
Concise Bible Commentary
The proud Syrians were beaten, and the despised Israelites were conquerors. The orders of the proud, drunken king disordered his troops, and prevented them from attacking the Israelites. Those that are most secure, are commonly least courageous. Ahab slew the Syrians with a great slaughter. God often makes one wicked man a scourge to another.
SDA Bible Commentary (limited)
Volume 1-7
18. Take them alive. In his haughtiness Benhadad ordered all the Hebrews to be seized, whether they had come out to negotiate terms of peace, whether they were offering to surrender, or whatever their purpose might be.