This is quite a transformation from Psalm 101. Whereas in the last psalm we saw a very confident (I would probably even say at best brash and at worst cocky) author who was able to proclaim: “I will destroy the wicked in the land.” In this Psalm we read the author humbly confess: “he has broken my strength in midcourse, he has shortened my days.” Again, context is everything. If Psalm 101 was written pre-Bathsheba and this psalm was written post, maybe even after the death of Absalom, it all makes sense.
We find in this Psalm a cry for help as the author bemoans the fact that his bones burn like a furnace (sounds like old age to me), and he is too tired to even eat bread. But the contrast is found in vs.12 where he speaks that the Lord is enthroned forever and that His name shall endure for all generations.
The author is able to lay down the perspective of this psalm by reaching back even to creation itself as he states: “Long ago you laid the foundation of the earth, and the heavens are the work of your hands.” All of this is really for the purpose of leaving a legacy behind. The legacy is so that “the children of your servants shall live secure, their offspring shall be established in your presence.”
This legacy is not anything material, but rather as vs. 18 states: that the faithfulness of the Lord will be recorded for generations to come and that even those who are unborn would praise the Lord. That is strong statement for making sure that we make this world a better place for future generations. This is an even stronger statement that we pass on our faith from one generation to the next.