Hebrews 6:13

Τῷ γὰρ Ἀβραὰμ ἐπαγγειλάμενος ὁ Θεός, ἐπεὶ κατ' οὐδενὸς εἶχεν μείζονος ὀμόσαι, ὤμοσεν καθ' ἑαυτοῦ,

Tō gar Abraam epaggeilamenos o Theos, epei kat' oydenos eichen meizonos omosai, ōmosen kath' eaytoy,

King James Version (KJV)

For when God made promise to Abraham, because he could swear by no greater, he sware by himself,

Modern English

When God made his promise to Abraham, since there was no one greater for him to swear by, he swore by himself,