The Gemara relates: And on another occasion, the descendants of Ishmael and the descendants of Keturah came to judgment with the Jewish people before Alexander of Macedon. They said to the Jewish people before Alexander: The land of Canaan is both ours and yours, as it is written: “And these are the generations of Ishmael, son of Abraham, whom Hagar the Egyptian, Sarah’s maidservant, bore unto Abraham” (Genesis 25:12), and it is written: “And these are the generations of Isaac, son of Abraham” (Genesis 25:19). Therefore, the land should be divided between Abraham’s heirs. Geviha ben Pesisa said to the Sages: Give me permission and I will go and deliberate with them before Alexander of Macedon. If they will defeat me, say to them: You have defeated an ordinary person from among us, and until you overcome our Sages, it is no victory. And if I will defeat them, say to them: The Torah of Moses, our teacher, defeated you, and attribute no significance to me. The Sages gave him permission, and he went and deliberated with them. Geviha ben Pesisa said to the descendants of Ishmael: From where are you citing proof that the land of Canaan belongs to both you and the Jewish people? They said to him: From the Torah. Geviha ben Pesisa said to them: I too will cite proof to you only from the Torah, as it is stated: “And Abraham gave all that he had to Isaac. But to the sons of the concubines that Abraham had, Abraham gave gifts, and he sent them away from his son, while he yet lived, eastward, to the east country” (Genesis 25:5–6). In the case of a father who gave a document of bequest [agatin] to his sons during his lifetime and sent one of the sons away from the other, does the one who was sent away have any claim against the other? The father himself divided his property. The Gemara asks: What were these gifts that Abraham gave to the sons of the concubines? Rabbi Yirmeya bar Abba says: This teaches that Abraham provided them with the name of the supernatural spirit of impurity, enabling them to perform witchcraft.