זוהר בראשית — דף קלט ע”א

The Zohar explains that Jacob had to act with guile toward Esau so that the serpent could not rule or defile the Sanctuary; Abraham and Isaac had no such need, since Esau had not yet come into the world. On the verse “the boys grew,” each went his own way, one toward faith and the other toward idolatry, as already in Rebecca’s womb. Esau is “a man of the field,” whose portion lies in a desolate place rather than in the settled world. The text asks how Isaac could be unaware of Esau’s deeds, and answers that the Divine Presence was with him but did not inform him, so that Jacob would be blessed according to the will of the Holy One, blessed be He. A story then begins: the companions question Rabbi Shimon about the matter of the birthright.