Matthew 5:33-37 - The Sermon On The Mount: Taking Oaths
33 Again, you have heard that it was said by the ancients, You shall not swear falsely, but shall perform to the Lord your oaths. 34 But I tell you, Swear not at all; neither by heaven, for it is God's throne; 35 nor by the earth, for it is his footstool, nor by Jerusalem, for it is the city of the great King; 36 nor swear by your head, for you cannot make one hair white or black. 37 But let your speech be, yes, yes, and no, no; for any thing more than this is evil.