The Zohar explains the mystical meaning of Sarah’s role as sister to Abraham. In the Zohar it sheds light on the Shekinah. Twice Abraham said of Sara, “She is my sister.” On the first occasion he referred to the Shekinah, who was constantly with Sarah, and as Abraham was of the right side he could indeed say of the Shekinah “She is my sister,” using the term in the same mystic sense as in the verse, “my sister, my love, my dove, my undefiled.” Abraham always called her “sister” because he was attached to her inseparably. Abraham says, “moreover she is my sister, the daughter of my father: the daughter of Supernal Wisdom, for which reason she is called “my sister” and also Wisdom- “but not the daughter of my mother”- from the place where is the origin of all most hidden and recondite. “And so she became my wife”, by way of fondness and affection. Abraham never deviates from the true faith. By referring to Sarah as his sister he is claiming the same indissoluble kinship as between brother and sister.
What Abraham saw in Egypt was all the people were worshipping the stars and constellations, Abraham, the true believer, avowed “she is my sister”, as much to say “We two will never separate.” Abraham and Sarah cleave to God.
When God created man in his perfect state, man and woman were side by side (androgynous). When the female separated from the male they were then face to face. No longer one being but two separate beings. A man who cleaves to God is said to be at the right side of God. Such a man whom cleaves to God is called holy, perfect, wholly devoted to God.
The Shekinah is not found in the company of sinners, but when a man exerts himself to purify himself and to draw near to God, then the Shekinah rests on him.
When the man and wife are joined together and are called by one name, then the celestial favors rest upon them. The word for “God” signifies the radiance of Wisdom into two Hebrew letters He, signifying the female; the letter Vau, signifying the male; when they are joined the holy neshamah is united to this spot.
For it is the path taken by man in this world that determines the path of the soul on her departure. For it is by his acts, by his words, and his devotion that he can draw to himself that spirit on high. If man follows a certain direction in this world he will be led further in the same direction when he departs this world; as that to which he attaches himself in this world, so is that to which he will find himself attached in the other world: if holy, holy, and if defiled, defiled. If he cleaves to holiness he will on high be drawn to that side. Similarly if he clings to uncleanliness, he will be drawn there towards that side and be made one of the unclean company and be attached to them.
(Deau. 10:20) “Who shall ascend into the mountain of the Lord?” And the answer given,” He that hath clean hands and a pure heart.”
(Ps. 24:3-4) , that is he that has not made with his hands vain shapes nor grasped with them wrongful objects, nor has he defiled himself through them like those who defile their bodies wilfully.
Reference~ The Zohar, Volume 1