(Isa. 4:4)
“Washing away the filth of the daughters of Zion” and “purging the blood of Jerusalem” recalls the ancient sacrifices in which the burnt offerings were rinsed to remove impurities, the cleansing atonement of Christ, and washings and anointings.
(Victor L. Ludlow, Isaiah: Prophet, Seer, and Poet [Salt Lake City: Deseret Book Co., 1982], 110.)