Why Scripture calls Melchizedek without father and without mother
Eustathius opens his treatise by taking up Paul's description of Melchizedek as without mother and without father, and begins to explain why Scripture omits his ancestry.
Paul expressed Melchizedek as without mother and without father. No one could deny that Melchizedek, the greatest of priests, did not spring up from the earth. He did not grow from an oak or from a rock, nor was he taken from the ground and molded as clay, formed and shaped by hands as Adam was.
And a little further on: What then might someone say? Melchizedek is reported to us as without mother. Yet if he is like God and the Word and in every way resembles him, bearing his image and preserving his character, he is not without mother or without father. For Christ has a mother, Mary, and a royal lineage from David, and from the root of Jesse the flower of the whole fragrance to us springs up, and his lineage according to the flesh is traced in a genealogy. But Melchizedek's line is seen to be without genealogy.
So someone might say that Melchizedek is without genealogy because he is not from the seed of Abraham and was never traced in a genealogy by Moses, but is a Canaanite by descent and comes from that accursed sowing. He was shown righteous by his own deeds, not descended from righteous ancestors or from any righteous sowing.
It was not lawful, then, to trace a genealogy and lead back to the line of Canaan the man who inclined toward the height of righteousness. Nor was it at all fitting to join the one who had taken hold of the height of righteousness to the line that had taken hold of the height of unrighteousness. Therefore Scripture says he is without father and without mother, because it does not consider his ancestors worthy of the virtue of the righteous and self-controlled man.
Greek
De Melchisedech (fragmenta) Ἀμήτορά που καὶ ἀπάτορα τὸν Μελχισεδὲκ ἐξέφρασεν ὁ Παῦλος. Ὅτι μὲν τοίνυν ἐκ γῆς οὐκ ἀνέτειλεν ὁ μέγιστος τῶν ἱερέων Μελχισεδέκ, οὐδεὶς ἀντειπεῖν ἔχοι· οὐδὲ γὰρ ἐκ δρυὸς οὐδ' ἀπὸ πέτρας ἔφυ, οὐδ' ἐκ γῆς ληφθεὶς πηλουργεῖται κατὰ τὸν Ἀδὰμ πλαττόμενος καὶ τῶ χεῖρε πλαστουργεῖται. Καὶ μετ' ὀλίγον τόπον· Τί οὖν ἄν τις εἴποι; ἀμήτωρ γὰρ ἡμῖν ὁ Μελχισεδὲκ ἱστορεῖται. Καίτοι γε εἰ ἐμφερὴς τυγχάνοι τῷ Θεῷ καὶ Λόγῳ καὶ τὸ ξύμπαν ἡμῖν ἔοικεν αὐτῷ τὴν ἐκείνου φέρων εἰκόνα καὶ τὸν ἐκείνου σώζων χαρακτῆρα, οὐκ ἀμήτωρ οὐκ ἀπάτωρ ἐστίν· ἔστι γὰρ τῷ Χριστῷ καὶ μήτηρ Μαρία καὶ γένος τὸ βασιλικὸν τοῦ ∆αυὶδ καὶ ἐκ τῆς ῥίζης τοῦ Ἰεσσαὶ τὸ τῆς ὅλης ἡμῖν εὐωδίας ἄνθος ἀνατέλλει καὶ γενεαλογεῖται τὸ κατὰ σάρκα γένος αὐτοῦ, τὸ δὲ τοῦ Μελχισεδὲκ ἀγενεαλόγητον εἶναι θεωρεῖται. Οὐκοῦν εἴποι τις ἂν τὸν Μελχισεδὲκ ἀγενεαλόγητον εἶναι διὰ τὸ μὴ εἶναι ἐκ τοῦ σπέρματος Ἀβραὰμ μηδὲ ὑπὸ Μωσέως γενεαλογεῖσθαι πώποτε, εἶναι δὲ Χαναναῖον τὸ γένος καὶ ἐκ τῆς ἐπαράτου ἐκείνης σπορᾶς ὁρμᾶσθαι, δίκαιον δὲ τῶν καθ' ἑαυτὸν ἀποφανθέντα καὶ οὐκ ἐκ προγόνων ὁρμώμενον δικαίων οὐδ' ἀπό τινος δικαίας σπορᾶς. Οὐ θέμις οὖν ἦν γενεαλογεῖν καὶ εἰς τὸ τοῦ Χαναὰν γένος ἀνάγειν τὸν εἰς ἄκρον δικαιοσύνης νεύοντα, οὐδὲ γὰρ πρεπωδέστατον ἦν τὸν τῆς ἄκρας δικαιοσύνης ἐπιλελημμένον συμπλέκειν τῷ τῆς ἄκρας ἀδικίας ἐπιλελημμένῳ γένει. ∆ιὸ ἀπάτορα καὶ ἀμήτορά φησιν αὐτὸν εἶναι ἡ γραφή, οὐκ ἀξίους τοὺς προγόνους ἡγουμένη τῆς ἀρετῆς τοῦ δικαίου καὶ σώφρονος ἀνδρός.