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
John Chrysostom
AD 407
Here again, not as wondering at man, has He withdrawn him from swearing by his head (for so man himself would be worshipped), but as referring the glory to God, and signifying that you are not master even of yourself, and of course therefore not of the oaths made by your head. For if no one would give up his own child to another, much more will not God give up His own work to you. For though it be your head, yet is it the property of another; and so far from being master thereof, you shall not be able to do with it, no not the least thing of all. For He said not, You can not make one hair grow; but, Not so much as change its quality.
But what, it may be said, if any one should require an oath, and apply constraint? Let the fear of God be more powerful than the constraint: since, if you are to bring forward such excuses, you will keep none of the things which are enjoined.
Yea, for first with respect to your wife you will say, what if she be contentious and extravagant; and then as to the right eye, what if I love it, and am quite on fire? and of the unchaste look, what then, if I cannot help seeing? and of our anger against a brother, what if I be hasty, and not able to govern my tongue? and in general, all His sayings you may on this wise trample under foot. Yet surely with regard to human laws you dare not in any case use this allegation, nor say, what then if this or that be the case, but, willing or unwilling, you receive what is written.
And besides, you will never have compulsion to undergo at all. For he that has hearkened unto those former blessings, and has framed himself to be such as Christ enjoined, will have no such constraint to endure from any, being held in reverence and veneration by all.
