Matthew 5:36

nor shall you swear by your head, for you cannot make a single hair white or black.

Matthew 6:27

Which of you can add an ell to his height by troubling about it?

Matthew 23:16-21

Woe to you, blind guides that you are! you say, 'Swear by the sanctuary, and it means nothing; but swear by the gold of the sanctuary, and the oath is binding.'

Luke 12:25

Which of you can add an ell to his height by troubling about it?

Treasury of Scripture Knowledge

Summary

Neither shalt thou swear by thy head, because thou canst not make one hair white or black.

General references

Bible References

Shalt

Matthew 23:16
Woe to you, blind guides that you are! you say, 'Swear by the sanctuary, and it means nothing; but swear by the gold of the sanctuary, and the oath is binding.'

Because

Matthew 6:27
Which of you can add an ell to his height by troubling about it?
Luke 12:25
Which of you can add an ell to his height by troubling about it?

General references

Luke 12:25
Which of you can add an ell to his height by troubling about it?