We should not abuse the name of God by using it to swear.
40. Deuteronomy 10:20. You shall fear the Lord your God and serve him, you shall cling to him and make your oaths in his name.
41. Hezekiel 17:19. As surely as I live, says the Lord, I will bring down on his head my oath which has has despised, and my covenant which he has broken.
42. Matthew 5:34,37. But I say to you, that you should not swear at all. Let your speech simply be like this: let your "yes" be "yes" and your "no" be "no". Anything beyond this from evil.