When the Lord shall have washed away the filth... — This serves as the connecting link with Isaiah 3:16-24. The prophet has not forgotten the daughters of Zion. Jehovah will wash away, as with the baptism of repentance, the “filth,” the moral uncleanness, that lay beneath their outward show of beauty. The “blood of Jerusalem,” in the next verse, has a wide range of meaning, from the “murders” of Isaiah 1:15; Isaiah 1:21, to the Moloch sacrifices in which the women had borne a conspicuous part (Psalms 106:38; Isaiah 57:5; Ezekiel 22:2-3).
By the spirit of judgment, and by the spirit of burning. — The word for “spirit” is better taken in its more literal meaning, as breath or blast, as in Isaiah 30:27-28; Isaiah 40:7. The words indicate that the prophet saw in the “blood” of which he speaks a greater enormity than that of the daughters of Zion. The one might be washed away. The other needed, as it were, the “fiery baptism” of the wrath of Jehovah. (Comp. Isaiah 30:27; Matthew 3:11.) The Authorised Version “burning” represents the root-meaning of the word, but it is elsewhere (Isaiah 6:13; Deuteronomy 13:5; Deuteronomy 17:7) used for “destruction” generally.