Hebrews 6:13

10 For God is not unrighteous to forget your work and labour of love, which ye have shewed toward his name, in that ye have ministered to the saints, and do minister.

11 And we desire that every one of you do shew the same diligence to the full assurance of hope unto the end:

12 That ye be not slothful, but followers of them who through faith and patience inherit the promises.

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

14 Saying, Surely blessing I will bless thee, and multiplying I will multiply thee.

15 And so, after he had patiently endured, he obtained the promise.

16 For men verily swear by the greater: and an oath for confirmation is to them an end of all strife.