John Calvin Commentary Psalms 35:27

"Let them shout for joy, and be glad, that favor my righteous cause: Yea, let them say continually, Jehovah be magnified, Who hath pleasure in the prosperity of his servant." — Psalms 35:27 (ASV)

Let those who favor my righteous cause rejoice and be glad. These two expressions, which are rendered in the optative mood, might have been translated with equal propriety in the future tense; but as this is a matter of little consequence, I leave it undecided. David here extols the deliverance which he asks of God, and exults in the results which should flow from it; namely, that it would be an occasion of general rejoicing and good hope to all the godly, while at the same time it would stir them up to celebrate the praises of God.

He attributes to all the faithful the desire that, as an innocent man, his righteous cause should be maintained. David, it is true, was the object of almost universal hatred among the simple and unsuspecting, who were deceived by false and unjust reports made concerning him; but it is certain that there were some among the people who formed a just and impartial estimate of things, and who were sorely grieved that a holy man, and one whose benevolence was also well known, should have been so unjustly and wrongfully oppressed.

And surely the common feelings of humanity require that when we see people unjustly oppressed and afflicted, if we are not able to help them, we should at least pity them. When David uses the language, Jehovah be magnified, his design seems to be to tacitly set this in opposition to the pride of the wicked, which he mentioned above. As they presume in the pride of their hearts, and by their insolent and overbearing conduct, to obscure, as far as lies in their power, the divine glory, so the faithful may, on the other hand, with good reason present the prayer that God would shine forth in the majesty of his character, and truly demonstrate that he exercises a special care over all his servants and takes a special pleasure in their peace. Finally, the Psalmist again declares, in the conclusion of the psalm, his resolution to celebrate in appropriate praises the righteousness of God, by which he had been preserved and delivered.