Matthew Henry on Psalms 99:6-9

The happiness of Israel is made out by referring to the most useful governors of that people. They in every thing made God's word and law their rule, knowing that they could not else expect that their prayers should be answered. They all wonderfully prevailed with God in prayer; miracles were wrought at their request. They pleaded for the people, and obtained answers of peace. Our Prophet and High Priest, of infinitely greater dignity than Moses, Aaron, or Samuel, has received and declared to us the will of the Father. Let us not only exalt the Lord with our lips, but give him the throne in our heart; and while we worship him upon his mercy-seat, let us never forget that he is holy.