36 And do not swear by your head, for you cannot make even one hair white or black.

Read Matthew 5:36 Using Other Translations

Neither shalt thou swear by thy head, because thou canst not make one hair white or black.
And do not take an oath by your head, for you cannot make one hair white or black.
Do not even say, ‘By my head!’ for you can’t turn one hair white or black.