Let me know, Jehovah, my end,
And how much is the measure of my days;
Know how fragile I am.
What words of the psalmist! How much humility and truth in what he says! really the knowledge that every man must understand
The psalmist says help me understand how fragile I am so that the ego does not want to go to my head help me understand how fragile I am so that even in my best moments I can have a memory of you and he says help me understand that as a shadow it is my life and life happens that just as we had a day of entry here we have a day of departure on the agenda here and David says let me understand because if I forget it it may be that I act in rebellion because when we remember how weak and fragile we are but we recognize God in our lives and we will always have a praise to God in our mouths
and David keeps saying in Psalms 103: 1-6
Bless my soul Jehovah, and bless all my being his holy name. 2 Bless Jehovah, my soul, and do not forget any of its benefits. 3 He it is who forgives all your iniquities, He who heals all your ailments; 4 The one that rescues your life from the hole, The one that crowns you with favors and mercies; 5 He who satisfies your mouth with good So that you rejuvenate yourself like the eagle. 6 Jehovah is the one who does justice and the right to all who suffer violence.
We are fragile and we have learned that we are vulnerable and any adversity can ruin our plans, so we must recognize our fragility and the need for God in our lives. David had faithfully studied the law which had become commonplace for him to incorporate quotes on the merciful and forgiving character of God in his songs.
Man's condition is literally dust and David acknowledges it with humility and God's need when he likens life as an herb to describe the shortness of life but praises God and attributes everything he sees in it to his true creator, Jehovah.