Psalms 103:2

Bless the Lord, O my soul
Which is repeated to show the importance of the service, and the vehement desire of the psalmist, that his soul should be engaged in it:

and forget not all his benefits;
not any of them; the least of them are not to be forgotten, being such as men are altogether unworthy of; they flow not from the merit of men, but from the mercy of God; and they are many, even innumerable; they are new every morning, and continue all the day; and how great must the sum of them be, and not one should be forgotten; and yet even good men are very apt to forget them; as the Israelites of old, who sung the praises of the Lord, and soon forgot his works: the Lord, knowing the weakness of his people's memories, has not only, under the Gospel dispensation, appointed an ordinance, to be continued to the end of the world, to commemorate a principal blessing and benefit of his, redemption by his Son; but has also promised his Spirit, to bring all things to their remembrance; and this they should be concerned for, that they do remember what God has done for them, in order both to show gratitude and thankfulness to him, and for the encouragement of their faith and hope in him.