Hebrews 6:16

13 For when God made his oath to Abraham, because there was no greater oath, he made it by himself,

14 Saying, Be certain that I will give you my blessing, and make your numbers very great.

15 And so, when he had been waiting calmly for a long time, God's word to him was put into effect.

16 For men at all times make their oaths by what is greater; and any argument is ended by the decision of the oath.

17 So that when it was God's desire to make it specially clear to those who by his word were to have the heritage, that his purpose was fixed, he made it more certain with an oath;

18 So that we, who have gone in flight from danger to the hope which has been put before us, may have a strong comfort in two unchanging things, in which it is not possible for God to be false;

19 And this hope is like a strong band for our souls, fixed and certain, and going in to that which is inside the veil;