Matthew 5:33-37 - The Sermon On The Mount: Taking Oaths
33 You were also told that you should keep a promise (oath). Always keep your promises (vows) to Jehovah. 34 I tell you, offer no promises at all, not by heaven, because it is God's throne. 35 Not by earth, for it is the footstool under His feet. Not by Jerusalem, for it is the city of the great King. 36 And do not promise by your head, for you cannot even control the hair on your head. 37 Let your answer be 'Yes' or 'No.' Anything more than this is from the evil one.