The spiritual entity Zeir Anpin – Small Countenance - is one of the five spiritual entities that exist in the Cosmic Worlds. After God has created the world for the first time, the souls, not being able to resemble their Creator in His ability of giving, did burst, or break. God reconstructed five entities from the shards, and now they could give to each other. Zeir Anpin is one of them.
Abraham, Rachel, and Leah are not only personalities, but are also physical representations of the spiritual regions in Zeir Anpin. Initially Abraham was lower in Zeir Anpin than Rachel. Now God is telling Abraham that he should leave the lower land and direct himself to the upper Land, Israel, represented by Leah.
That is why God called this land “which I will show you.” At the time of Abraham, Zeir Anpin did not have fully developed brain, or capacity to understand, and the area of Leah in Zeir Anpin was not revealed nor seen – because it can only be understood with a fully developed capacity for understanding. That is what God meant when he told Abraham, “I will make you a great nation” - that Abraham will develop the brain of Zeir Anpin, and through this development all will be able to see and understand the spiritual quality represented in the world by Leah, who in turn represents the Land of Israel.
Art: Henry Mosler - The Broken Sabot