What does 2 Samuel 10:6 mean?

The Ammonites realized they had made David angry, so they hired 20,000 Aramean soldiers from Beth Rehob and Zobah, plus the king of Maacah with 1,000 men, and 12,000 men from Tob. 2 Samuel 10:6 - Modern Text Bible

(The Ammonites know they’ve started a fight, so they hire mercenaries from nearby regions to help them.)