זוהר במדבר — דף קלא ע”ב

The Zohar teaches that one who bonds with a woman from other nations receives a spirit of impurity, and the son born from him inherits an impure soul. Abraham knew that Eliezer had merited the holy covenant (Brit ha-Kodesh), and therefore trusted him to seek a wife for Yitzhak. The Zohar emphasizes that the nations of Canaan had fundamentally defiled the holy covenant, which is why Abraham's seed was commanded not to take a wife from the daughters of Canaan. Rabbi Elazar concludes by opening the verse: 'Uncover my eyes that I may behold wonders from Your Torah'.