HKB
we conclude, that in this command he vindicates his just claims, and guards the sanctity of his name, but does not teach the duties which men owe to each other.
XXIII. In the first place, we have to explain what an oath is. It consists in calling upon God as a witness, to confirm the truth of any declaration that we make. For execrations, which contain manifest reproaches against God, are not worthy to be mentioned among oaths. That such an attestation, when rightly performed, is a species of Divine worship, is evident from many places of Scripture; as when Isaiah prophesies of the vocation of the Assyrians and Egyptians to participate in the covenant with Israel. “They shall speak,” says he, “the language of Canaan, and swear to the Lord of hosts.”(843) By “swearing to the Lord” here is intended making a profession of religion. Again, when he speaks of the extension of his kingdom: “He who blesseth himself in the earth shall bless himself in the God of truth; and he that sweareth in the earth shall swear by the God of truth.”(844) Jeremiah says, “If they will diligently learn the ways of my people, to swear by my name, The Lord liveth; as they taught my people to swear by Baal, then shall they be built in the midst of my people.”(845) And we are justly said to profess our religion to the Lord, when we invoke his name to bear witness to us. For thereby we confess that he is truth itself, eternal and immutable; whom we call not only as a witness of the truth, excelling all others, but also as the only defender of it, who is able to bring to light things which are concealed, and in a word, as the searcher of all hearts. For where human testimonies are wanting, we resort for refuge to the testimony of God; and particularly when any thing is to be affirmed, which is hidden in the conscience. For which reason the Lord is extremely angry with them who swear by strange gods, and interprets that species of swearing as a proof of manifest defection from him. “Thy children have forsaken me, and sworn by them that are no gods.”(846) And he declares the atrociousness of this crime by his denunciation of punishment: “I will cut off them that swear by the Lord, and that swear by Malcham.”(847)
XXIV. Now, since we understand it to be the will of the Lord, that we should reverence his name in our oaths, we ought to use so much the more caution, lest, instead of reverence, they betray dishonour or contempt of it. It is no trifling insult to him, when perjury is committed in his name; and therefore the law calls it a profanation.(848) But what remains to the Lord, when he is despoiled of his truth? he will then cease to be God. But he is certainly despoiled of it, when he is made an abettor and approver of a falsehood. Wherefore, when Joshua would induce Achan to a confession of the truth, he says, “My son, give, I pray thee, glory to the Lord God of Israel;”(849) implying in this that the Lord is grievously dishonoured, if perjury be committed in his name. Nor is this strange; for in such a case we do all that is in our power to brand his sacred name with a falsehood. And that this form of expression was customary among the Jews, whenever any man was called to take an oath, appears from a similar adjuration used by the Pharisees in the Gospel of John.(850) To this caution we are accustomed by the forms of oaths which are used in the Scriptures: “The Lord liveth;”(851) “God do so and more also to me;”(852) “I call God for a record upon my soul;”(853) which imply, that we cannot invoke God to be a witness to our declarations, without imprecating his vengeance upon us if we be guilty of perjury.