The heavens declare his righteousness - See the notes at Psalms 50:6. Compare the notes at Psalms 19:1.
And all the people see his glory - As manifested in the heavens, and in the power which he puts forth on the earth. That is, (they have the opportunity of seeing it; it is made manifest in all his works. They see what in fact is a manifestation of his glory, to wit, his great and wondrous works. It is not affirmed that they “appreciate” all this, or that they see this to be a manifestation of his glory - which would not be true - but that they see what is in fact a revelation of his greatness, his wisdom, and his power.