Neither shall you swear by your head, because you can not make one hair white or black.
All Commentaries on Matthew 5:36 Go To Matthew 5
Theophylact of Ochrid
AD 1107
God alone swears by Himself as He is not subject to anyone or anything. Since we do not have authority over ourselves, how can we swear by our own head? It is the property of another. But if you think your head is your own, then change one hair of it if you can.
