Tumah

 Kuzari (3 49) The Rabbi: Impurity and holiness are contradictory ideas; one cannot be thought of without the other. Without holiness we should not know the signification of impurity. Impurity means that the approach to holy objects, hallowed by God, is forbidden to the person so affected. Such would be priests, their food, clothing, offering, sacrifices, the holy House, etc. In the same way the ideas of holiness include something which forbids the person connected with it to approach many ordinary objects. This chiefly depends on the vicinity of the Shekhinah, which we now lack entirely. The prohibition which still holds good, of cohabiting with a woman in her period or after confinement has nothing to do with impurity, but is an independent divine law. The practice we observe to keep aloof from them as much as possible is but a restriction and hedge to prevent cohabitation. The regulations of impurity proper ceased to exist for us, because we live in 'an unclean land and in unclean air,' especially as we move about among graves, vermin, lepers, persons affected with issue, corpses, etc.

Zohar (1:64a) As the Left Arm above grasps the Female and lovingly draws her to him, so below the serpent, which is the left arm of the unclean spirit, and joined with it he that rides on it, draw near to the moon and draw her tightly to them, so that she becomes defiled. Israel, therefore, here below offer up a goat, to which the serpent is drawn away. The moon then purges herself, ascends on high, and unites herself to the higher sphere to receive blessing, and her lower face, which was darkened, becomes bright. So here on the Day of Atonement, since the evil serpent is occupied with the he-goat, the moon breaks loose from him, and earnestly pleads the cause of Israel, and watches over them like a mother over her children, so G-d blesses them from above and forgives their sins. Afterwards, when Israel celebrate the Feast of Tabernacles, the “right side” is awakened on high, so that the moon may attach herself to it and her face may become completely bright. She then shares out blessings to all those presiding chiefs of the lower world, so that they may be fully occupied with their own portions, and not attempt to draw sustenance from the side from which Israel obtained their portion. 

Zohar (1 70a) G-d will one day sweep away the unclean spirit, as it is written, And the unclean spirit I will cause to pass out of the land, and further, He will swallow up death for ever, and the Lord God will wipe away tears from all faces, and the reproach of his people will he take away from off all the earth, for the Lord hath spoken it. God  will also one day restore the moon to its full light, and dissipate the darkness brought on her by the evil serpent, as it is written, And the light of the moon shall be as the light of the sun, and the light of the sun shall be sevenfold, as the light of the seven days , the reference here being to the primordial light which G-d stored away during the period of the creation.’

Zohar (1 125b) ‘I marvel at the wicked Balaam, how all his actions proceeded from the side of impurity. We here learn the mystical lesson that all species of witchcraft are linked up with, and proceed from, the primeval serpent who is the foul and unclean spirit. Hence all sorceries are called serpents. And whoever becomes addicted to them pollutes himself, nay more, he has first to become polluted in order to attract to himself the side of the unclean spirit. For it is a dictum of our teachers that corresponding to the impulses of a man here are the influences which he attracts to himself from above. Should his impulse be towards holiness, he attracts to himself holiness from on high and so he becomes holy; but if his tendency is towards the side of impurity, he draws down towards himself the unclean spirit and so becomes polluted. For this reason, in order to draw towards himself the unclean spirit from that supernal serpent, the wicked Balaam besmirched himself nightly by bestial intercourse with his ass, and he would then proceed to his divinations and sorceries. To begin with he would take one of the familiar serpents, tie it up, break