Charles Ellicott Commentary Amos 2:1

"Thus saith Jehovah: For three transgressions of Moab, yea, for four, I will not turn away the punishment thereof; because he burned the bones of the king of Edom into lime:" — Amos 2:1 (ASV)

Compare Isaiah 15-16, Isaiah 25:10–12, and Jeremiah 48:0. Translate burned to lime the bones of the king of Edom. The historical reference is obscure. (See 2 Kings 3:26–27.) Whether Moab was guilty of desecrating royal tombs, or offering the heir of the king of Edom in sacrifice, cannot be determined. When Moab took revenge upon Edom, the latter was subject to Jehoram.