Psalm 51:7

Purify me with hyssop, and I shall be clean: Wash me, and I shall be whiter than snow.

Isaiah 1:18

Come now, and let us reason together, saith Jehovah: though your sins be as scarlet, they shall be as white as snow; though they be red like crimson, they shall be as wool.

Hebrews 9:19

For when every commandment had been spoken by Moses unto all the people according to the law, he took the blood of the calves and the goats, with water and scarlet wool and hyssop, and sprinkled both the book itself and all the people,

1 John 1:7

but if we walk in the light, as he is in the light, we have fellowship one with another, and the blood of Jesus his Son cleanseth us from all sin.

Exodus 12:22

And ye shall take a bunch of hyssop, and dip it in the blood that is in the basin, and strike the lintel and the two side-posts with the blood that is in the basin; and none of you shall go out of the door of his house until the morning.

Leviticus 14:4-7

then shall the priest command to take for him that is to be cleansed two living clean birds, and cedar wood, and scarlet, and hyssop:

Leviticus 14:49-52

And he shall take to cleanse the house two birds, and cedar wood, and scarlet, and hyssop:

Numbers 19:18-20

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:

Ephesians 5:26-27

that he might sanctify it, having cleansed it by the washing of water with the word,

Hebrews 9:13-14

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:

Revelation 1:5

and from Jesus Christ, who is the faithful witness, the firstborn of the dead, and the ruler of the kings of the earth. Unto him that loveth us, and loosed us from our sins by his blood;

Revelation 7:13-14

And one of the elders answered, saying unto me, These that are arrayed in white robes, who are they, and whence came they?

Treasury of Scripture Knowledge

Summary

Purge me with hyssop, and I shall be clean: wash me, and I shall be whiter than snow.

Bible References

Purge

Leviticus 14:4
then shall the priest command to take for him that is to be cleansed two living clean birds, and cedar wood, and scarlet, and hyssop:
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:
Hebrews 9:19
For when every commandment had been spoken by Moses unto all the people according to the law, he took the blood of the calves and the goats, with water and scarlet wool and hyssop, and sprinkled both the book itself and all the people,

And

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:
1 John 1:7
but if we walk in the light, as he is in the light, we have fellowship one with another, and the blood of Jesus his Son cleanseth us from all sin.
Revelation 1:5
and from Jesus Christ, who is the faithful witness, the firstborn of the dead, and the ruler of the kings of the earth. Unto him that loveth us, and loosed us from our sins by his blood;

Whiter

Isaiah 1:18
Come now, and let us reason together, saith Jehovah: though your sins be as scarlet, they shall be as white as snow; though they be red like crimson, they shall be as wool.
Ephesians 5:26
that he might sanctify it, having cleansed it by the washing of water with the word,
Revelation 7:13
And one of the elders answered, saying unto me, These that are arrayed in white robes, who are they, and whence came they?

General references

Leviticus 15:5
And whosoever toucheth his bed shall wash his clothes, and bathe himself in water, and be unclean until the even.
Leviticus 16:30
for on this day shall atonement be made for you, to cleanse you; from all your sins shall ye be clean before Jehovah.
Numbers 19:6
and the priest shall take cedar-wood, and hyssop, and scarlet, and cast it into the midst of the burning of the heifer.

American Standard Version Public Domain