The Odyssey 24.545–548
So spoke Athena, and he obeyed, and was glad at heart. Then for all time to come a solemn covenant betwixt the twain was made by Pallas Athena, daughter of Zeus, who bears the aegis, in the likeness of Mentor both in form and in voice.
ὣς φάτʼ Ἀθηναίη, ὁ δʼ ἐπείθετο, χαῖρε δὲ θυμῷ.
ὅρκια δʼ αὖ κατόπισθε μετʼ ἀμφοτέροισιν ἔθηκεν
Παλλὰς Ἀθηναίη, κούρη Διὸς αἰγιόχοιο,
Μέντορι εἰδομένη ἠμὲν δέμας ἠδὲ καὶ αὐδήν.