Matthew 5:34

But I say unto you, Swear not at all; neither by heaven; for it is God’s throne:

Christ's command forbids using oaths in ordinary speech to back up what is said, whether by calling on heaven and earth as witnesses, swearing by one's life or head, or invoking destruction on oneself if the word is false. Heaven and earth, Jerusalem and even one's own body cannot be pledged in such swearing, for heaven is God's throne, earth His footstool, Jerusalem His city, and everything possessed comes from God and was bought by Christ's blood. Solemnly calling God to witness when lawfully required to testify in court is not a violation of this word when the truth is spoken. The prohibition states a principle of His kingdom of grace that reaches beyond outward acts to the spirit of the law in the heart, and it is to be believed and practiced until divine principles shape a Christlike character.

Sermon Setting and Authority

Jesus spoke this command on a level place on the mountainside as part of the Sermon on the Mount. It was given especially to His disciples gathered close about Him, but within hearing of the gathered multitude. The people had come from many regions to hear Him and to be healed, and His words were designed to reach the hearts and consciences of that mixed crowd assembled. The teaching was addressed not to the disciples alone but also to the assembled multitude.

It states principles that govern His kingdom of divine grace. In doing so it disappointed the hopes of the believing Jews for earthly glory, for freedom from the yoke of bondage, and for restoration to ancient glory.

The Sermon contradicted the doctrines and practices of the self-righteous scribes and Pharisees. It contrasts His authoritative instruction with the repeated sayings of the rabbis. His teaching, rather than unstable human wisdom, is the certain wisdom to follow.

He speaks in it with an authority that belongs to Him alone, and His words come from God. Yet the Sermon is simple enough for a child to study without being misled.

Meaning of the Prohibition

Swear not at all forbids swearing by heaven, by earth, by Jerusalem, or by one's own head, because none of these belong to the one who swears: heaven is God's throne, earth is His footstool, Jerusalem is His city, and a person cannot control even the color of a hair. Everything possessed comes from God and has been bought by Christ's blood, so there is nothing a person owns to pledge as though it were his own. The warning is aimed at oaths used in ordinary conversation to prove a statement true, including exaggerating and reinforcing claims by swearing by one's life or head. It also includes calling heaven and earth to witness, or invoking destruction upon oneself and wishing to be struck out of existence if the statement is false.

The prohibition does not forbid judicial oaths. Solemnly calling God as witness when lawfully required to testify, and when it is necessary, is not a violation of God's word when the truth is spoken.

The command belongs to His teaching on the law that reveals its far-reaching principles and claims, rather than treating the law as a cold code of commands and traditions. It shows that the claims of the law require the spirit of the law in the heart, because the state of the heart regulates life and character, and teaching the law is lost unless these far-reaching principles are impressed. The law given on the mount is the foundation of God's throne and remains the standard of righteousness as long as heaven and earth endure. It reaches into every part of life, condemns every evil action, and demands perfect obedience.

Call to Practice Obedience

The teaching in Matthew 5 is to be believed and practiced, and living by it develops Christlike character and puts divine principles in the heart.
Its words give a clear, definite expression of His will and are to be dwelt upon often, so that divine virtues are brought constantly into life. Those who will to do the will of God will know true doctrine, holding the standard high without spot or wrinkle. This includes putting away unkind, retaliatory words that separate friends.

The command belongs to the law given on the mount, which reaches into every part of life, condemns every evil action, and demands perfect obedience. It belongs also to authoritative instruction that stands in contrast to the repeated sayings of the rabbis, showing that His teaching rather than unstable human wisdom is the certain wisdom to follow.