O give thanks unto the LORD. The exhortation is intensely earnest: the Psalmist pleads with the Lord's people with an "O", three times repeated. Thanks are the least that we can offer, and these we ought freely to give. The inspired writer calls us to praise Jehovah for all his goodness to us, and all the greatness of his power in blessing his chosen. We thank our parents, let us praise our heavenly Father; we are grateful to our benefactors, let us give thanks unto the Giver of all good. For he is good. Essentially he is goodness itself, practically all that he does is good, relatively he is good to his creatures. Let us thank him that we have seen, proved, and tasted that he is good. He is good beyond all others: indeed, he alone is good in the highest sense; he is the source of good, the good of all good, the sustainer of good, the perfecter of good, and the rewarder of good. For this he deserves the constant gratitude of his people. For his mercy endureth for ever. We shall have this repeated in every verse of this song, but not once too often. It is the sweetest stanza that a man can sing. What joy that there is mercy, mercy with Jehovah, enduring mercy, mercy enduring for ever. We are ever needing it, trying it, praying for it, receiving it: therefore let us for ever sing of it.
"When all else is changing within and around,
In God and his mercy no change can be found."