John Calvin Commentary Psalms 89:2

"For I have said, Mercy shall be built up for ever; Thy faithfulness wilt thou establish in the very heavens." — Psalms 89:2 (ASV)

For I have said, Mercy shall be built up for ever. He assigns the reason why he perseveres in singing the Divine praises in the midst of adversities; this reason is that he does not despair of the manifestation of God’s loving-kindness toward His people, although at present they were under severe chastisement.

Never will a man freely open his mouth to praise God unless he is fully persuaded that God, even when angry with His people, never lays aside His fatherly affection toward them. The words I have said, imply that the truth which the inspired writer sets forth was deeply fixed in his heart.

It is as if he had said: "Whatever has happened until now, it has never succeeded in erasing from my heart the undoubted hope of experiencing Divine favor in the future, and I will always continue steadfastly to cherish this same hope."

It should be noted that it was not without a painful and arduous conflict that he succeeded in embracing by faith the goodness of God, which at that time had entirely vanished from sight. This point, we stress, should be particularly noted, so that when God at any time withdraws from us all the tokens of His love, we may nevertheless learn to erect in our hearts that everlasting building of mercy spoken of here—a metaphor signifying that Divine mercy will be extended, or will continue until it reaches its end or consummation.

In the second clause of the verse, something must be supplied. In short, the meaning is that the Divine promise is no less stable than the settled course of the heavens, which is eternal and exempt from all change. By the word heavens, I understand not only the visible skies but also the heavens that are above the whole structure of the world; for the truth of God, in the heavenly glory of His kingdom, is placed above all the elements of the world.