Matthew 5:33-37
5:33 "Again you have heard that it was said to those of old, 'You shall not swear falsely, but shall perform your oaths to the Lord.'
5:34 But I say to you, do not swear at all: neither by heaven, for it is God's throne;
5:35 nor by the earth, for it is His footstool; nor by Jerusalem, for it is the city of the great King.
5:36 Nor shall you swear by your head, because you cannot make one hair white or black.
5:37 But let your 'Yes' be 'Yes,' and your 'No,' 'No.' For whatever is more than these is from the evil one.