Then will I sprinkle clean water upon you, and ye shall be clean: from all your filthiness, and from all your idols, will I cleanse you.
Then will I sprinkle clean water upon you, and ye shall be clean. The external restoration must be preceded by an internal one. The change in their condition must not be superficial, but must be based on a radical renewal of the heart. Then the pagan, understanding from the regenerated lives of God's people how holy God is, would perceive Israel's past troubles to have. been only the necessary vindications of His righteousness. Thus, God's name would be "sanctified" before the pagan, and God's people be prepared for outward blessings.
Sprinkle ... water - phraseology taken from the law: the "water of separation" used in the "purification for sin" of those unclean-namely, the water taken from a running stream and mixed with the ashes of a heifer, and sprinkled with a hyssop on the unclean (Numbers 19:9-18); the thing signified being the cleansing blood of Christ sprinkled on the conscience and heart (Hebrews 9:13-14; Hebrews 10:22; cf. Jeremiah 33:8; Ephesians 5:26).
From all your idols, will I cleanse you. Literal idolatry has ceased among the Jews ever since the captivity-so far the prophecy has been already fulfilled; but 'cleansing from all their idols,' e.g., covetousness, prejudices against Jesus of Nazareth, is yet future.