Charles Ellicott Commentary Jeremiah 25:33

"And the slain of Jehovah shall be at that day from one end of the earth even unto the other end of the earth: they shall not be lamented, neither gathered, nor buried; they shall be dung upon the face of the ground." — Jeremiah 25:33 (ASV)

They shall not be lamented ... — As in other depictions of slaughter (Jeremiah 8:2; Jeremiah 16:4), the omission of the usual burial rites serves to intensify their misery. The corpses of the slain are to lie rotting on the ground. The phrase slain of the Lord reproduces Isaiah 66:16.