Psalms 102:24

What then does the prophet mean when he prays, Let us not perish in the midst of our course? (160) The reason stated in the clause immediately following, Thy years are from generation to generation, seems to be quite inapplicable in the present case. Because God is everlasting, does it therefore follow that men will be everlasting too? But on Psalms 90:2, we have shown how we may with propriety bring forward his eternity, as a ground of confidence in reference to our salvation; for he desires to be known as eternal, not only in his mysterious and incomprehensible essence, but also in his word, according to the declaration of the Prophet Isaiah,

“All flesh is grass, and all the goodliness thereof is as the flower of the field; but the word of our God shall stand for ever.”
Isaiah 40:6

Now since God links us to himself by means of his word, however great the distance of our frail condition from his heavenly glory, our faith should nevertheless penetrate to that blessed state from which he looks down upon our miseries. Although the comparison between his eternal existence and the brief duration of human life is introduced also for another purpose, yet when he sees that men pass away as it were in a moment, and speedily evanish, it moves him to compassion, as shall presently be declared at greater length.