John Calvin Commentary Psalms 128:5

"Jehovah bless thee out of Zion: And see thou the good of Jerusalem all the days of thy life." — Psalms 128:5 (ASV)

Jehovah shall bless you from Zion. Some would have this sentence be a prayer, and therefore they interpret the future tense in the optative mood. But it seems rather to be a continued statement of the same doctrine previously dwelt on, with the Prophet now expressing more plainly that the benefits he has recounted are to be ascribed to God as their author.

Although the gifts of God often present themselves before our eyes, yet through the obscurity that false imaginations cast upon them, our perception of them is dim and imperfect. Therefore, this repetition of the sentiment—that whenever true believers experience any prosperous events in the course of their life, it is the effect of the divine blessing—should not be considered superfluous.

The persons described are said to be blessed from Zion, to lead them to remember the covenant God had entered into with them, for He had graciously promised to be favorable to those who observe His law; and they had imbibed these principles of godliness from their infancy.

The Prophet, therefore, declares that what he presents is not a novel doctrine or something previously unheard of. The law had long ago taught them that it is made manifest, even by the temporary benefits conferred on those who serve God, that the efforts made in serving Him are not wasted; and he affirms that they will actually experience this.

What is added concerning the good of Jerusalem should be regarded as enjoining upon the godly the duty not only of seeking their own individual welfare or of being devoted to their own particular interests, but rather of having as their chief desire to see the Church of God in a flourishing condition.

It would be a very unreasonable thing for each member to desire what may be profitable for itself, while in the meantime the body was neglected. Because of our extreme proneness to err in that respect, the Prophet, with good reason, recommends concern for the public welfare. He mingles domestic blessings and the common benefits of the Church in such a way as to show us that they are things joined together, and which it is unlawful to put asunder.