Kabbalah к Бамидбар 23:23

This is the meaning of what Bilaam, Laban's grandson, said, "Surely there is no enchantment in Jacob, nor divination in Yisrael" (Num. 23:23). For who could prevail against them when my grandfather wished to destroy their father with divination and enchantment but could not, not having obtained permission to curse from the Holy One, blessed be He, as it is written, "Surely there is no enchantment in Jacob, nor divination in Yisrael."