Psalm 135:19-21 Bless the Lord, O house of Israel: bless the Lord, O house of Aaron. bless the Lord, O house of Levi: ye that fear the Lord, bless the Lord. Blessed be the Lord out of Zion, which dwelleth at Jerusalem. Praise ye the Lord.
instead of building and worshipping man-made idols, all the priests and people of God are called upon to bless the Lord and praise Him alone above all gods. There is no other God but the Lord alone, so we worship and bless Him as the only God, the source of all good.
Blessing is to say good things about God to the Lord. He is always all good, He does good to us, and His mercy endures forever. Therefore, our weekly and daily response is to thank and praise, worship and bless Him with our words and deeds. Our sinful response to perceived bad things is to curse God, like Job, or to use His name to curse things.
God has given us our tongue, which we can use to either bless or to curse. It is obvious to us what we are to do with it. James 3:9-10: “With it (the tongue) we bless our Lord and Father, and with it we curse people who are made in the likeness of God. From the same mouth come blessing and cursing. My brothers, these things ought not to be so.” How different life would be if we always used the tongue to bless God and other people. The Gospel is the power of God moving us to always give a blessing to God in every circumstance.