John Calvin Commentary Isaiah 51:8

"For the moth shall eat them up like a garment, and the worm shall eat them like wool; but my righteousness shall be for ever, and my salvation unto all generations." — Isaiah 51:8 (ASV)

But my righteousness shall continually endure. Because the believing servants of God must endure many reproaches and slanders from the enemies of the word, the Prophet exhorts and encourages them to bear it courageously. It frequently happens that we are more deeply moved by the scorn and insults of men than by fire and sword; but we ought to consider it praise and glory to be the object of their contempt and abhorrence. True valor springs from this consideration, that, although the world rejects us as filth and offscourings (1 Corinthians 4:13), God esteems us, because we maintain the same cause with Him. Let us with Moses, therefore, prefer the reproach of Christ to the treasures of the Egyptians (Hebrews 11:26). Let us rejoice with the Apostles, who

departed from the council glad and joyful, because they were accounted worthy to suffer shame for the name of Jesus (Acts 5:41).

And my salvation for ever and ever. Because the death of wicked men would offer us little consolation if we were not saved, he shows what our condition will be, namely, that we shall never be left without God’s righteousness and salvation. But the comparison may seem inappropriate when he contrasts the destruction of the wicked with His righteousness.

It might have been expressed more clearly and suitably in this way: “though the reprobate indulge in merriment, yet they shall quickly perish; but believers, though they appear to be dead, shall live.” Again, because he makes no mention of us, and highlights only the eternity of God’s righteousness, it may be objected that this is of no use to us who are almost overwhelmed.

But by these words the Prophet instructs us that in our afflictions we should seek consolation from the thought that our health and salvation are, as it were, secured in God. For, as long as men trust or rely on themselves, they cannot hold onto any good hope that does not quickly decay; and therefore we should turn our hearts to God, whose mercy endureth from everlasting to everlasting on them that fear him, as David says, and his righteousness to children’s children (Psalms 103:17).

Because salvation is founded on the goodness of God, Isaiah reminds us of it, so that men may be reduced to nothing, and that confidence may be placed in God alone. The meaning may be summarized as follows: “Salvation is in God, so that by it He may preserve, not Himself, but us; righteousness is in God, so that He may display it for our defense and preservation.” Accordingly, from the eternity of God’s salvation and righteousness, we should infer that the servants of God cannot possibly perish; which agrees with the passage from David quoted a little earlier,

Thou art the same, and thy years shall not fail. The children of thy servants shall dwell, and their posterity shall be established for ever (Psalms 102:27, 28).

Thus we see how he applies this eternity to the children of God, who do not subsist in themselves, but in God, and have the foundation of their salvation in Him.