Psalms 39:4

Lord, make me to know mine end, give him the proper understanding of the vanity of this earthly life and the quickness with which it is cut off, and the measure of my days, what it is, that this measure may soon be filled up; that I may know how frail I am, a mortal being in the midst of perishable things. This thought is intended to stress, not so much the shortness of human life, as its utter vanity and therefore the folly of concerning one's self with the matters of this world to the exclusion of the one thing needful, the laying hold of God in faith and trust.