Origen of Alexandria, Against Celsus 22
After this, Celsus does not attack circumcision as a Jewish practice; instead he claims it originated with the Egyptians, trusting Egyptian testimony over Moses, who says Abraham was the first man to be circumcised. It is not Moses alone who records Abraham's name as belonging to God; many who conjure demons also invoke the phrase "the God of Abraham" in their incantations. They do this because of the name itself and the implied kinship between God and the righteous one, so they adopt the formula "the God of Abraham" even though they do not actually know who Abraham is. The same must be said of Isaac, Jacob, and Israel; these admittedly Hebrew names are scattered throughout Egyptian magical texts that promise some kind of power. The history of circumcision, which begins with Abraham and is prohibited by Jesus because he does not want his disciples to practice it, is not for interpretation now. The present moment is not for teaching on these matters but for dismantling the charges Celsus brings against the Jewish narrative, since he thinks he can more quickly disprove Christianity if he can show its Jewish origins to be false.
Greek
Μετὰ ταῦτα τὸ περιτέμνεσθαι τὰ αἰδοῖα μὴ διαβαλὼν ὁ Κέλσος ὑπὸ Ἰουδαίων γινόμενον, φησὶν ἀπὸ Αἰγυπτίων αὐτὸ ἐληλυθέναι, Αἰγυπτίοις μᾶλλον ἢ Μωϋσεῖ πιστεύσας, λέγοντι πρῶτον ἐν ἀνθρώποις περιτετμῆσθαι τὸν Ἀβραάμ. τοῦ δ᾿ Ἀβραὰμ τὸ ὄνομα οὐ Μωυσῆς ἀναγράφει μόνος οἰκειῶν αὐτὸν θεῷ, ἀλλὰ γὰρ καὶ πολλοὶ τῶν ἐπᾳδόντων δαίμονας χρῶνται ἐν τοῖς λόγοις αὐτῶν τῷ „ὁ θεὸς Ἀβραὰμ,“ ποιοῦντες μὲν διὰ τὸ ὄνομα καὶ τὴν πρὸς τὸν δίκαιον τοῦ θεοῦ οἰκειότητα, διὸ παραλαμβάνουσι τὴν „(ὁ) θεὸς Ἀβραὰμ“ λέξιν. οὐκ ἐπιστάμενοι δὲ, τίς ἐστιν ὁ Ἀβραάμ. τὰ δ᾿ αὐτὰ λεκτέον καὶ περὶ τοῦ Ἰσαὰκ καὶ περὶ τοῦ Ἰακὼβ καὶ περὶ τοῦ Ἰσραήλ· ἅτινα ὁμολογουμένως Ἑβραῖα ὄντα ὀνόματα πολλαχοῦ τοῖς Αἰγυπτίοις ἐπαγγελλομένοις ἐνέργειάν τινα ἐνέσπαρται μαθήμασι. τὸν δὲ λόγον τῆς περιτομῆς, ἀρξάμενον ἀπὸ τοῦ Ἀβραὰμ καὶ κωλυόμενον ὑπὸ τοῦ Ἰησοῦ, μὴ βουλομένου τοὺς ἑαυτοῦ μαθητὰς τὸ αὐτὸ ποιεῖν. οὐ πρόκειται νῦν ἑρμηνεύειν. οὐ γὰρ τῆς περὶ τούτων διδασκαλίας ὁ παρὼν καιρὸς ἀλλ᾿ ἀγῶνος καθαιροῦντος τὰ φερόμενα ὑπὸ Κέλσου κατὰ τοῦ Ἰουδαίων λόγου ἐγκλήματα, οἰομένου τάχιον ψευδοποιήσειν τὸν χριστιανισμὸν, ἐὰν τῆς ἀρχῆς αὐτοῦ ἐν τοῖς Ἰουδαϊκοῖς οὔσης λόγοις κατηγορῶν παραστήσῃ κἀκεῖνον ψευδῆ.