Charles Ellicott Commentary 2 Samuel 8:6

"Then David put garrisons in Syria of Damascus; and the Syrians became servants to David, and brought tribute. And Jehovah gave victory to David whithersoever he went." — 2 Samuel 8:6 (ASV)

Garrisons. —The primary meaning of this word in the original language is something placed, and then placed over. Hence it comes to have the different derived meanings of officer in 1 Kings 4:5; 1 Kings 4:19; 2 Chronicles 8:10, and garrison (1 Samuel 10:5; 1 Samuel 13:3), which is probably its meaning here.