John Calvin Commentary Isaiah 62:8

"Jehovah hath sworn by his right hand, and by the arm of his strength, Surely I will no more give thy grain to be food for thine enemies; and foreigners shall not drink thy new wine, for which thou hast labored:" — Isaiah 62:8 (ASV)

Jehovah hath sworn. He proceeds with the metaphors which he previously used. Since, due to the corruption of our nature, the kingdom of Christ cannot be described in a way that is understandable to us, it was necessary to represent it figuratively.

Just as he first promised an abundance of all things, and then faithful guardianship, so that the condition of believers might be safe; so here he promises tranquility and repose, that they may peacefully enjoy their blessings and may not in the future be dispossessed of them.

It is as if he had said, “Whatever you previously had in your hands was exposed to plunder and robbery; but now you will have everything well secured, and will freely partake of your corn and your wine; and, in a word, you will enjoy your prosperity in peace.”

But since the depravity of our nature is such that we do not place trust in God, even though he promises generously and bountifully, this is why the Prophet represents him as swearing; for the Lord condescends to us so much as to use an oath, in order to further correct our unbelief and obstinacy.

Now, the Lord sweareth by himself, because (as an Apostle says) he hath none greater than himself. (Hebrews 6:13)

By his right hand and by the arm of his strength. He mentions his right arm, that is, the power of God, because that was appropriate to the present discussion.

It is as if he had said, “If I have any power, I will display it in your salvation; and lest, in a difficult matter, your minds should grow dull, I swear by my hand, which is invincible and victorious over all, that whatever difficulties may arise, you will be safe under my protection.”

Therefore, whenever he promises salvation, let us think of his strength and power.

If I shall give. This is an elliptical form of expression; and by it we are taught the sacredness and solemnity of an oath. The meaning of this declaration is as if he had said that he wishes that from now on he may not be believed if these promises are not fulfilled by the outcome.

When he promises the peaceful enjoyment of wheat and wine, he means that it was a result of his righteous judgment, and did not happen by chance, that the Church was deprived of corn and wine. For whenever enemies ravage and plunder, this is unquestionably done by God’s permission, as he threatens in the Law (Deuteronomy 28:33). On the other hand, it is his special blessing that everyone eats in safety under his vine, and under his fig-tree. (1 Kings 4:25)