זוהר בראשית — דף קכו ע”ב

In the continuing conversation, Rabbi Yosi observes to Rabbi Yitzhak that at Mount Sinai the defilement ceased from Israel, but not from the nations that had not received the Torah. Rabbi Yitzhak replies that the Torah was given to males only, women being exempt from the commandments, and that after the sin all returned to their defilement. According to the Zohar, it is harder to separate the defilement from a woman, and sorcery is found more among women because they proceed from the left side and the severe judgment; the text states this as an explanation concerning that side alone. It recalls that Balaam first defiled himself, and warns against approaching a woman during her days of impurity, as the Torah states. Finally, it asks why observing the chirping of birds is called “serpent,” and says the serpent will be removed from the world in the future.