Then washed I thee with water; yea, I throughly washed away thy blood from thee, and I anointed thee with oil.
Then washed I thee - as brides used to pass through a preparatory purification (Esther 2:12). So Israel, before the giving of the law at Sinai (Exodus 19:14, "Moses sanctified the people, and they washed their clothes"). So believers (1 Corinthians 6:11).
Oil - emblem of the Levitical priesthood, the type of Messiah (Psalms 45:7).