And he put garrisons in Edom; throughout all Edom put he garrisons, and all they of Edom became David's servants. And the LORD preserved David whithersoever he went.
He put garrisons in Edom - with a view to secure his acquisition of so important a dependency. It was, however, after the commencement of the war with the Syrians, and probably on a personal visit to Petra (Psalms 9:9; Psalms 108:11).