This revokes the oath making of the earlier Dispensation. When an oath was taken it was to be performed without fail. (See, e.g., Numbers 30: 2.) It was binding. Ancient Israel relied on vows to govern their conduct. (See, e.g., 1 Nephi 4: 33-37.) Oaths were relied on because they bound your conduct before God.

Christ is putting an end to the practice. No further vow-making was to take place. In its place say “yea” or say “nay,” but nothing further to bind your soul before God.

 

Swearing by men who possess nothing is foolish and prideful. Particularly when they swear by heaven, because it is not theirs to promise.  Nor should they swear by the earth, because it is not theirs either.  A man cannot even offer his own life, because it belongs to God who gave it. Indeed, there is nothing we own or can offer. (Mosiah 2: 20-25.)

 

The comment regarding the inability to make a single hair “black or white” is emphasizing how little control we really have over things. Even our own bodies will take a course assigned it by God. They will age, and eventually die. We have our body as a stewardship. It is ours for a season, then we will lay it down. Until then, we serve a probation in which we are given power over these elements we occupy. But that stewardship is one designed to “prove” us, and show what we really are. When we gratify the body at the expense of others, or destroy our bodily temple housing our spirits by indulging uncontrolled appetites, we are unwise. We will lose these bodies before long and then, left with the same spiritual emptiness which caused the cravings in the first place, will find ourselves suffering. Whereas, if you discipline the body, keep it under control and subject to your spirit, then death can bring a release and freedom from suffering. It will be an odd reversal. One known only to those who go through it; at which point it is too late to change the outcome.

 

Additionally, Christ is suggesting that we speak in plain language, without the rhetoric of grand threats or promises. Speak simply. Speak out of an abundance of humility. Mean what you say, and do not obligate yourself to do what you cannot do.

 

Live simply, prepare to deal honestly with one another. And leave the heavens out of your promises if you cannot control them.

 

Do not commit yourself to do anything by swearing to God it shall be done. You have no control over when you will die, whether you will have another day of health to accomplish what you have vowed, or even if the thing about which you committed yourself will continue to be possible. Be humble about what you are given. Be grateful.

 

These verses address a social standard that needed to be left behind. Coming out of that should be a replacement of plain speaking, humility about what we are able to do, and caution about words we use.

In this reformation alone Christ proves Himself to be a sage. He was more than a wise teacher, He was the Great Teacher. This concept alone makes Him one of the greatest social reformers of the ancient world.