Question:

The Torah records that Abraham gave presents to the children he had with Hagar. Rashi says that they were filled up with tumah (dark spiritual forces). Why would Abraham do that? Why not just throw it away and give something good to them?

Answer:

The verse you're referring to is in Genesis 25:6:

And to the sons of Abraham's concubines, Abraham gave gifts, and he sent them away from his son Isaac while he [Abraham] was still alive, eastward to the land of the East.

The actual words of the Talmud (Sanhedrin 91a) about these gifts are "he gave them the name of tumah." Simply understood, this implies that he gave them impure powers. However, there are obvious difficulties with this. First, as you asked, why would he want give them something evil? Second, the Torah forbids the use of black magic—how could Abraham encourage it?

This question was asked by several of the commentators of the Torah, particularly of note, are the following answers given by the 12th century Tosafists.

Some explain this Talmudic statement to mean that he gave them the right to use the name of G‑d even when in a state of physical impurity. This explanation, too, raises a difficulty. If Abraham saw them as unfit to carry on his legacy, why would he teach them and give them abilities to say the holy name of G‑d?

Therefore, most others explain that this means that he taught them how to protect themselves from the forces of tumah such as demons. This is referred to as "the name of tumah" because by knowing the names of theses negative energies they would be able to instruct them to do their will and remove them.

However, the following explanation brought in the commentary of Riva (Rabbi Isaac ben Asher II) on the Torah, is the one I found most fascinating. He points to Genesis 4:26 where the verse states that in the generation of Enoch "it became common to call by the name of the L‑rd." This is explained by the Midrash to mean that, "they would name people and idols with the name of the Holy One, blessed be He, to make them idols and to call them deities." Therefore, Abraham taught his children "the name of tumah"; i.e. he taught them names for their idols that would connote the tumah associated with them, instead of calling them with names used for the one true G‑d.

There is an intriguing oft-quoted passage in the Zohar (Vol. 1 pp. 99b -100b) that sheds much light on these gifts and their relationship to the "land of the East," which may well be the Indus Valley. You can find that on our site at: Kabbalah and the East and Abraham's Presents to the East - The Zohar. From that passage, it would seem that the gifts were originally wholesome wisdom, but were later diverted to negative and impure uses.