Origen

“ After this, Celsus, without condemning circumcision as practised by the Jews, asserts that this usage was derived from the Egyptians; thus believing the Egyptians rather than Moses, who says that Abraham was the first among men who practised the rite. And it is not Moses alone who mentions the name of Abraham, assigning to him great intimacy with God; but many also of those who give themselves to the practice of the conjuration of evil spirits, employ in their spells the expression “God of Abraham,” pointing out by the very name the friendship (that existed) between that just man and God. ”