Parallel
Hebrews 6:13
Patriarchal Greek New Testament (1904) · Berean Standard Bible
Τῷ γὰρ Ἀβραὰμ ἐπαγγειλάμενος ὁ Θεός, ἐπεὶ κατ᾽ οὐδενὸς εἶχε μείζονος ὀμόσαι, ὤμοσε καθ᾽ ἑαυτοῦ,
When God made His promise to Abraham, since He had no one greater to swear by, He swore by Himself,