For when God made promise to Abraham, because he could swear by no greater, he sware by himself,
Berean Study Bible (BSB) - Hebrews 6:13 >When God made His promise to Abraham, since He had no one greater to swear by, He swore by Himself,
Textus Receptus (TR) - Hebrews 6:13 >Τῷ γὰρ Ἀβραὰμ ἐπαγγειλάμενος ὁ Θεός, ἐπεὶ κατ᾿ οὐδενὸς εἶχε μείζονος ὀμόσαι, ὤμοσε καθ᾿ ἑαυτοῦ,