Hebrews 9:13

For if the blood of goats and of bulls, and the ashes of an heifer sprinkled on the unclean, can cleanse them from external impurities;

2 Corinthians 5:21

for he hath made him who knew no sin to be a sin-offering for us, that we might be justified by God thro' him.

2 Corinthians 7:1

since then, we have these promises, my dear brethren, let us cleanse our selves from all impurity, whether of body or mind, perfecting holiness in the fear of God.

Hebrews 7:26

and indeed we wanted an high priest of such a character, one that is holy, innocent, undefiled, one that is separated from sinful men, and exalted above the heavens; one who was under no necessity,

Treasury of Scripture Knowledge

Summary

And a man that is clean shall gather up the ashes of the heifer, and lay them up without the camp in a clean place, and it shall be kept for the congregation of the children of Israel for a water of separation: it is a purification for sin.

A water of separation

Bible References

Clean

2 Corinthians 5:21
for he hath made him who knew no sin to be a sin-offering for us, that we might be justified by God thro' him.
Hebrews 7:26
and indeed we wanted an high priest of such a character, one that is holy, innocent, undefiled, one that is separated from sinful men, and exalted above the heavens; one who was under no necessity,
Hebrews 9:13
For if the blood of goats and of bulls, and the ashes of an heifer sprinkled on the unclean, can cleanse them from external impurities;

A water of separation

2 Corinthians 7:1
since then, we have these promises, my dear brethren, let us cleanse our selves from all impurity, whether of body or mind, perfecting holiness in the fear of God.