1 Kings 22:47

There was then no king in Edom, a deputy was king. Which had been the case from the times of David, who subdued Edom, and placed garrisons in it, and governors over it, 2 Samuel 8:14 and continued through the reign of Jehoshaphat, unto the times of his son, under whom the Edomites revolted, and set up a king of their own, 2 Kings 8:20, with a view to which this is observed, as also to account for it how Jehoshaphat could build ships in Eziongeber, which was in the land of Edom, of which in the next verse, because the whole country was governed by a viceroy, or deputy, under him.