The masters of the Kabbalah, of blessed memory, say that Abraham's
Rabbi, i.e., teacher, was the angel Zadkiel.
_Rabbi Menachem's comment on the Pent._, Exod. iii. 5.
Adam's book, which contained celestial mysteries and holy wisdom, came
down as an heirloom into the hands of Abraham, and he by means of it was
able to see the glory of his Lord.
THE TALMUD, _Zohar Parashah Bereshith._