Matthew 5:34-37

New Catholic Bible

³⁴ But what I tell you is this: Do not swear at all, either by heaven, since it is God’s throne, ³⁵ or by earth, since that is his footstool, or by Jerusalem, since that is the city of the great King. ³⁶ Nor should you swear by your head, for you cannot turn one hair of it white or black. ³⁷ All you need to do is to say ‘Yes’ if you mean ‘Yes’ and ‘No’ if you mean ‘No.’ Anything beyond this comes from the evil one.