Hebrews 6:13-18

Moffatt(i) 13 For in making a promise to Abraham God swore by himself (since he could swear by none greater), 14 I will indeed bless you and multiply you. 15 Thus it was that Abraham by his stedfastness obtained what he had been promised. 16 For as men swear by a greater than themselves, and as an oath means to them a guarantee that ends any dispute, 17 God, in his desire to afford the heirs of the Promise a special proof of the solid character of his purpose, interposed with an oath; 18 so that by these two solid facts (the Promise and the Oath), where it is impossible for God to be false, we refugees might have strong encouragement to seize the hope set before us,