Matthew 5:36
Neither shalt thou swear by thy head, because thou canst not make one hair white or black.
Cross-reference
Matthew 23:16–21
Parallel
Matthew 23:16-21 rebukes Pharisees for deceptive oaths by temple/gold — directly parallel to Jesus' teaching in Matthew 5:36 against swearing by one's head.
Matthew 6:27
Parallel
Matthew 6:27 similarly highlights human inability to change physical attributes, echoing the point about not controlling hair color.
Luke 12:25
Parallel
Luke 12:25 parallels the teaching on human powerlessness—cannot add a cubit to stature—mirroring the hair color point.