Charles H. Spurgeon on Psalms 67:3

Let the people praise thee, O God; let all the people praise thee. What then? "Then shall the earth yield her increase; and God, even our own God, shall bless us." We have comforts increased, the more we praise God for what we have already received. The more vapours go up, the more showers come down; as the rivers receive, so they pour out, and all run into the sea again. There is a constant circular course and recourse from the sea, unto the sea; so there is between God and us; the more we praise him, the more our blessings come down; and the more his blessings come down, the more we praise him again; so that we do not so much bless God as bless ourselves. When the springs lie low, we pour a little water into the pump, not to enrich the fountain, but to bring up more for ourselves. Thomas Manton.