ΠΡΟΣ ΑΦΟΒΟΝ
ἄρξομαι σημείωσαι, περὶ τοῦ θεολόγου.
ἐξομνύειν ὁ γὰρ μάρτυς ἀναγκάζεται καὶ περὶ τῶν οὐκ εἰδότων ἐξόμνυσθαι.
Beside the words 'I shall begin from here' in the third speech Against Aphobus, Demosthenes' defence of his witness Phanus, a reader notes that the Theologian, Gregory of Nazianzus, uses the same phrase. The only other note explains that a witness could be compelled to swear disclaimer even over matters they did not know.
Demosthenes Scholia Scholia on Demosthenes: Against Aphobus (Pros Aphobon) in Greek in PDF
Demosthenes Scholia Scholia on Demosthenes: Against Aphobus (Pros Aphobon) in Greek in MD
Part of Scholia on Demosthenes