Matthew 5:33-37

33 "You have heard that it was said to our people long ago, 'Don't break your promises, but keep the promises you make to the Lord.'

34 But I tell you, never swear an oath. Don't swear an oath using the name of heaven, because heaven is God's throne.

35 Don't swear an oath using the name of the earth, because the earth belongs to God. Don't swear an oath using the name of Jerusalem, because that is the city of the great King.

36 Don't even swear by your own head, because you cannot make one hair on your head become white or black.

37 Say only yes if you mean yes, and no if you mean no. If you say more than yes or no, it is from the Evil One.