Deuteronomy

Thou shalt not take the name of the Lord thy God in vain; for the Lord will not hold him guiltless that taketh his name in vain.

And I will come near to you to judgment; and I will be a swift witness against the sorcerers, and against the adulterers, and against false swearers, and against those that oppress the hireling in his wages, the widow, and the fatherless, and that turn aside the stranger from his right, and fear not me, saith the Lord of hosts.

And ye shall not swear by my name falsely, neither shalt thou profane the name of thy God: I am the Lord.

Thou shalt fear the Lord thy God, and serve him, and shalt swear by his name.

Again, ye have heard that it hath been said by them of old time, Thou shalt not forswear thyself, but shalt perform unto the Lord thine oaths: