My sword shall be bathed in heaven... — Literally, hath drunk to the full. The words find an echo in Deuteronomy 32:41-42, and Jeremiah 46:10. There, however, the sword is soaked, or made drunk with blood. Here it is “bathed in heaven,” and this seems to require a different meaning. We read in Greek poets, of the “dippings” by which steel was tempered. May not the “bathing” of Isaiah have a like significance?
It shall come down upon Idumea... — Better, for Edom, ... here and in the next verse. No reason can be assigned for this exceptional introduction of the Greek form.