Often we read about a physical, concrete concept in the Old Testament that has an abstract or spiritual counterpart. This counterpart is typically more prevalent in other scripture. The Law of Moses is one example. It is easy to get hung up on the rituals and rules that are found in Numbers and Leviticus and miss the fact that it all points to the Savior. A couple of other examples are found here and here.
We see the same trend reading about the concept of uncleanliness. The Book of Leviticus is obsessed with it. In Leviticus 11-15, words related to (un)cleanliness and (im)purity show up almost once per verse on average. These are instructions to Moses and Aron, primarily to ensure that no one enters into the Tabernacle unclean.
Thus shall ye separate the children of Israel from their ; that they die not in their uncleanness, when they defile my that is among them. (Leviticus 15:31)
The Priests of the tabernacle had a special duty to ensure that nothing unclean entered in and defiled it. There is much emphasis on separating the clean and holy from the unclean and unholy.
And ye may put difference between and unholy, and between and Leviticus 10:10)
God's word to Ezekiel just before the destruction of Jerusalem contains accusations of the priests not fulfilling this duty
Her have my law, and have profaned mine holy things: they have put no between the holy and profane, neither have they shewed difference between the unclean and the clean (Ezekiel 22:26)
When they do not manage to separate between the clean and unclean and when the people do not manage to rid themselves of the unclean, God needs to do the separation instead and it is much less pleasant than a ritual bath.
18 Son of man, the house of Israel is to me become : all they are brass, and tin, and iron, and lead, in the midst of the ; they are even the dross of silver.
19 Therefore thus saith the Lord God; Because ye are all become dross, behold, therefore I will gather you into the midst of Jerusalem.
20 As they gather silver, and brass, and iron, and lead, and tin, into the midst of the furnace, to blow the fire upon it, to melt it; so will I gather you in mine anger and in my fury, and I will leave you there, and melt you. (Ezekiel 22)
Our equivalent of the Jewish ritual bath, mikveh, is baptism by water. This is followed by baptism by fire, receiving the gift of the Holy Ghost. The fire symbolism has been discussed on this blog before (see here and here). The idea is that fire can purge us by removing the dross in us. This is the second step after being cleansed with water. But if we have indulged in the unclean without washing, we are the dross, and then the purging looks very different.
Why all this emphasis on separating the clean and unclean? Avoiding to defile the tabernacle/temple could perhaps be reason enough. Israelites believed that it was the House of God in a very real sense. But perhaps there also was a spiritual counterpart to this concept that the Israelites missed? Isaiah hints on that and the Book of Mormon expands on it. Let's have a look at Isaiah first. "Unclean" is brought up twice in chapter 52
, awake; put on thy , O ; put on thy , O , the holy city: for henceforth there shall no more come into thee the uncircumcised and the unclean. (Isaiah 52:1)
In this case, it is not only the temple where the unclean cannot enter, but the whole city of Jerusalem. This is describing a future state of Zion/Jerusalem, but still a place on earth (although perhaps in its millennial stage). Still speaking about this future time, Isaiah goes on to invite us to depart from Babylon in a second future exodus to Zion/the promised land.
Depart ye, depart ye, go ye from thence, no ; go ye of the midst of her; be ye , that bear the vessels of the Lord.
Jesus also talks about the latter-day gathering of Israel to the Nephites and quotes this verse in 3 Nephi 20:41. It also seems to be alluded to in at least two other Book of Mormon verses.
And now I say unto you, all you that are desirous to follow the voice of the , come ye out from the wicked, and be ye , and touch not their unclean things; and behold, their names shall be , that the names of the wicked shall not be numbered among the names of the righteous, that the word of God may be fulfilled, which saith: The names of the wicked shall not be mingled with the names of my people (Alma 5:57)
Hinting at the admonition by Isaiah, Alma adds "be ye separate" and goes on to explain that God wants to separate the names of the wicked and the names of his people. This idea is also rooted in ancient Jewish culture. The Law of Moses contained prohibitions to mingle certain types of grain or fabric, for example. Certain things had to be separated and kept separate. See Leviticus 19:19 and Deuteronomy 22:9-11. I am not sure if I understand the reason or symbolism behind the prohibition to plow with an ox and ass together or plant two different kinds of seeds in a field, but Alma applies this idea of separation on a more spiritual level.
Moroni 10:30 is another Book of Mormon verse alluding to Isaiah 52:11
And again I would exhort you that ye would unto Christ, and lay hold upon every good , and the evil gift, nor the .
He connects it with coming unto Christ, which is the symbolic equivalent of temple entrance for ancient Israelites.
But most Book of Mormon verses using the word "unclean", connect it with entering into the kingdom of God. The separation between the wicked and the righteous on that last day is the spiritual counterpart of all the separation issues and cleanliness before entering into the temple that we find in the Old Testament. Notice the temple reference in Alma 7:21, linking to us and our entrance into the kingdom of God
And he doth not dwell in temples; neither can filthiness or anything which is unclean be received into the kingdom of God; therefore I say unto you the time shall come, yea, and it shall be at the last day, that he who is shall remain in his filthiness.
As a final example, Nephi lays it out very plainly:
if their works have been filthiness they must needs be ; and if they be filthy it must needs be that they cannot in the kingdom of God; if so, the kingdom of God must be filthy also. But behold, I say unto you, the kingdom of God is not filthy, and there cannot any unclean thing enter into the kingdom of God; wherefore there must needs be a place of prepared for that which is filthy. (1 Nephi 15:33-34)
