John Calvin Commentary Psalms 146:5

"Happy is he that hath the God of Jacob for his help, Whose hope is in Jehovah his God:" — Psalms 146:5 (ASV)

Blessed is he, and so forth. Since it would not have been enough to rebuke the sin, the Psalmist presents the remedy on which its proper correction depends. This remedy is that human hopes are only firm and well-founded when they rest entirely on God.

For even the wicked sometimes go so far as to acknowledge the folly of trusting in humanity. Consequently, they are often angry with themselves for being so thoughtless as to expect deliverance from human beings; but by neglecting the remedy, they are not freed from their error.

The Psalmist, having condemned the delusion, which we have seen to be natural to us all, wisely adds that those who trust in God are blessed. Jeremiah observes the same order (Jeremiah 17:5, 7).

Cursed is he that trusteth in man, and maketh flesh his arm, and so forth;

And then—Blessed is the man whose hope the Lord is. When David declares those blessed whose help is the Lord, he does not limit the happiness of believers to their present experience, as if they were happy only when God openly and in visible actions appeared as their helper. Instead, he places their happiness in this—that they are truly convinced that they stand entirely by the grace of God.

He calls Him the God of Jacob to distinguish Him from the multitude of false gods in whom unbelievers boasted at that time. And there was good reason for this, because while all intend to seek God, few take the right way. In identifying the true God by His distinctive mark, the Psalmist suggests that it is only by an assured faith of adoption that any of us can rest upon Him, for He must show Himself gracious to us before we can look for help from Him.