Numbers 19:9

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 for impurity: it is a sin-offering.

Numbers 19:13

Whosoever toucheth a dead person, the body of a man that hath died, and purifieth not himself, defileth the tabernacle of Jehovah; and that soul shall be cut off from Israel: because the water for impurity was not sprinkled upon him, he shall be unclean; his uncleanness is yet upon him.

Hebrews 9:13

For if the blood of goats and bulls, and the ashes of a heifer sprinkling them that have been defiled, sanctify unto the cleanness of the flesh:

Numbers 19:20-21

But the man that shall be unclean, and shall not purify himself, that soul shall be cut off from the midst of the assembly, because he hath defiled the sanctuary of Jehovah: the water for impurity hath not been sprinkled upon him; he is unclean.

Leviticus 15:20

And everything that she lieth upon in her impurity shall be unclean: everything also that she sitteth upon shall be unclean.

Numbers 6:12

And he shall separate unto Jehovah the days of his separation, and shall bring a he-lamb a year old for a trespass-offering; but the former days shall be void, because his separation was defiled.

Numbers 8:7

And thus shalt thou do unto them, to cleanse them: sprinkle the water of expiation upon them, and let them cause a razor to pass over all their flesh, and let them wash their clothes, and cleanse themselves.

Numbers 9:13

But the man that is clean, and is not on a journey, and forbeareth to keep the passover, that soul shall be cut off from his people; because he offered not the oblation of Jehovah in its appointed season, that man shall bear his sin.

Numbers 19:18

and a clean person shall take hyssop, and dip it in the water, and sprinkle it upon the tent, and upon all the vessels, and upon the persons that were there, and upon him that touched the bone, or the slain, or the dead, or the grave:

Numbers 31:23-24

everything that may abide the fire, ye shall make to go through the fire, and it shall be clean; nevertheless it shall be purified with the water for impurity: and all that abideth not the fire ye shall make to go through the water.

Zechariah 13:1

In that day there shall be a fountain opened to the house of David and to the inhabitants of Jerusalem, for sin and for uncleanness.

2 Corinthians 5:21

Him who knew no sin he made to be'sin on our behalf; that we might become the righteousness of God in him.

2 Corinthians 7:1

Having therefore these promises, beloved, let us cleanse ourselves from all defilement of flesh and spirit, perfecting holiness in the fear of God.

Hebrews 7:26

For such a high priest became us, holy, guileless, undefiled, separated from sinners, and made higher than the heavens;

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.

Lay them up

General references

Bible References

Clean

Numbers 19:18
and a clean person shall take hyssop, and dip it in the water, and sprinkle it upon the tent, and upon all the vessels, and upon the persons that were there, and upon him that touched the bone, or the slain, or the dead, or the grave:
Numbers 9:13
But the man that is clean, and is not on a journey, and forbeareth to keep the passover, that soul shall be cut off from his people; because he offered not the oblation of Jehovah in its appointed season, that man shall bear his sin.
2 Corinthians 5:21
Him who knew no sin he made to be'sin on our behalf; that we might become the righteousness of God in him.
Hebrews 7:26
For such a high priest became us, holy, guileless, undefiled, separated from sinners, and made higher than the heavens;
Hebrews 9:13
For if the blood of goats and bulls, and the ashes of a heifer sprinkling them that have been defiled, sanctify unto the cleanness of the flesh:

Lay them up

Numbers 19:17
And for the unclean they shall take of the ashes of the burning of the sin-offering; and running water shall be put thereto in a vessel:

A water of separation

Leviticus 15:20
And everything that she lieth upon in her impurity shall be unclean: everything also that she sitteth upon shall be unclean.
Zechariah 13:1
In that day there shall be a fountain opened to the house of David and to the inhabitants of Jerusalem, for sin and for uncleanness.
2 Corinthians 7:1
Having therefore these promises, beloved, let us cleanse ourselves from all defilement of flesh and spirit, perfecting holiness in the fear of God.

General references

Leviticus 22:6
the soul that toucheth any such shall be unclean until the even, and shall not eat of the holy things, unless he bathe his flesh in water.
Numbers 19:18
and a clean person shall take hyssop, and dip it in the water, and sprinkle it upon the tent, and upon all the vessels, and upon the persons that were there, and upon him that touched the bone, or the slain, or the dead, or the grave:

American Standard Version Public Domain