Settled on his lees. Jeremiah compares Moab to wine that has never been drawn off into another container, and has thus absorbed the quality of its lees, or dregs.
Although their country had suffered varied political fortunes, the Moabites had never suffered deportation to a foreign land (they had “not been emptied from vessel to vessel”) which may have tended to keep them from absorbing fresh views of the world and new outlooks on life. Thus their provincialism grew into a national self-content that resulted in their downfall.