Matthew 5:36 YLT

³⁴  but I -- I say to you, not to swear at all; neither by the heaven, because it is the throne of God,

³⁵  nor by the earth, because it is His footstool, nor by Jerusalem, because it is a city of a great king,

³⁶  nor by thy head mayest thou swear, because thou art not able one hair to make white or black;

³⁷  but let your word be, Yes, Yes, No, No, and that which is more than these is of the evil.

³⁸  'Ye heard that it was said: Eye for eye, and tooth for tooth;