Charles Ellicott Commentary 2 Kings 12:20

"And his servants arose, and made a conspiracy, and smote Joash at the house of Millo, [on the way] that goeth down to Silla." — 2 Kings 12:20 (ASV)

His servants. — His immediate attendants. (Compare to 2 Kings 8:15).

Arose — that is, against him.

In the house of Millo. — Or, at Beth-Millo. The precise locality cannot be determined. Thenius supposes that the severely wounded (?) king had retired for greater safety into “the castle palace.” Ewald says the king was murdered while engaged in the fortress. For “the Millo,” see 2 Samuel 5:9; 1 Kings 9:15. The chronicler relates that Jehoash was murdered in his bed.

Which goeth down to Silla. — These words convey no meaning to us, the name Silla being otherwise unknown. The text is probably corrupt, for Silla is almost exactly like Millo in Hebrew writing. (The Vatican Septuagint omits “which goeth down.”)