When the Ammonites realized that they had become a stench to David, they hired twenty thousand Aramean foot soldiers from Beth-rehob and Zoba, as well as a thousand men from the king of Maacah and twelve thousand men from Tob.
Here we have, I. The preparation which the Ammonites made for war, Sa2 10:6. They saw they had made themselves very odious to David and obnoxious to his just displeasure. This they might easily have foreseen when they abused his ambassadors, which was no other than a challenge to war, and a bold defiance of him.
Commenting on 2 Samuel 10:6-14
And when the children of Ammon saw that they stank before David,.... Or had made themselves odious to him, as it is rendered in Ch1 19:6; were abominable to him, that he was incensed against them, and enraged at them, and was determined to be avenged on them for the affront given, of which they had certain information: but instead of seeking to appease him...
THE AMMONITES OVERCOME. (Sa2 10:6-14) when the children of Ammon saw that they stank before David--To chastise those insolent and inhospitable Ammonites, who had violated the common law of nations, David sent a large army under the command of Joab, while they, informed of the impending attack, made energetic preparations to repel it by engaging the services of an immense number of Syrian mercenaries.