Ben-hadad sent out, and they told him - The Septuagint has a better reading: “they sent and told the king of Syria.”
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
17. There are men. Since the sortie was made at noon, the approach was detected and there was not complete surprise. Word was sent to the king that a group of Hebrews was seen approaching.