(34-35) Neither by heaven;... nor by the earth;... neither by Jerusalem. — Other formulæ of oaths meet us in Matthew 23:16-22; James 5:12. It is not easy at first to understand the thought that underlies such modes of speech. When men swear by God, or the name of Jehovah, there is an implied appeal to the Supreme Ruler. We invoke Him (as in the English form, “So help me God”) to assist and bless us according to the measure of our truthfulness, or to punish us if we speak falsely. But to swear by a thing that has no power or life seems almost unintelligible, unless the thing invoked be regarded as endowed in idea with a mysterious holiness and a power to bless and curse. Once in use, it was natural that men under a system like that of Israel, or, we may add, of Christendom, should employ them as convenient symbols intensifying affirmation, and yet not involving the speaker in the guilt of perjury or in the profane utterance of the divine name. Our Lord deals with all such formulæ in the same way. If they have any force at all, it is because they imply a reference to the Eternal. Heaven is His throne, and earth is His footstool (the words are a citation from Isaiah 66:1), and Jerusalem is the city of the great King. To use them lightly is, therefore, to profane the holy name which they imply. Men do not guard themselves either against irreverence or perjury by such expedients.
Related Commentaries of Matthew 5:34
Matthew 5:34-35
34 But I say unto you, Swear not at all; neither by heaven; for it is God's throne:
35 Nor by the earth; for it is his footstool: neither by Jerusalem; for it is the city of the great King.