2 Corinthians 1:23

But I call God to witness to my soul, that sparing you I did not yet come into Corinth:

Hebrews 6:16

For men swear by the greater: and an oath of confirmation is to them an end to all controversy:

Treasury of Scripture Knowledge

Summary

Now therefore swear unto me here by God that thou wilt not deal falsely with me, nor with my son, nor with my son's son: but according to the kindness that I have done unto thee, thou shalt do unto me, and to the land wherein thou hast sojourned.

Bible References

Swear

2 Corinthians 1:23
But I call God to witness to my soul, that sparing you I did not yet come into Corinth:
Hebrews 6:16
For men swear by the greater: and an oath of confirmation is to them an end to all controversy: