We met with the same phrase applied to Coniah, Jeremiah 22:28. The meaning is, I have broken Moab all to pieces, as people use to do vessels they care not for; they never go about to mend such a vessel, but dash it in pieces against some stones or walls.
Related Commentaries of Jeremiah 48:38
Jeremiah 48:38
38 There shall be lamentation generally upon all the housetops of Moab, and in the streets thereof: for I have broken Moab like a vessel wherein is no pleasure, saith the LORD.