Albert Barnes Commentary Psalms 89:16

"In thy name do they rejoice all the day; And in thy righteousness are they exalted." — Psalms 89:16 (ASV)

In thy name shall they rejoice - In you they shall rejoice, or find their happiness. In your being; your perfections; your protection; your government; your favor.

All the day - That is, continually. It is their privilege, and it is their duty to rejoice always. You are always the same, and the happiness which is found in your being and attributes at one time may be found at all times; your promises are ever the same, and your people may find happiness in them always. There is no reason why the people of God should not be constantly happy; those who have such a God, and such hopes as they are permitted to cherish, should be so. Compare the notes at (Philippians 3:1); notes at (Philippians 4:4).

And in thy righteousness - Under your righteous government; or, in the knowledge of your righteous character.

Shall they be exalted - See (Proverbs 14:34). The effect of that knowledge shall be to exalt or to elevate them in moral character, in happiness, in the esteem of others, and in true prosperity. Compare (1 Timothy 4:8).