The brief nature of human existence presents a constant riddle about the meaning of life and the true value of our actions. We are faced with uncertainty on two fronts: an inability to recognize the right path in the present, and a complete blindness to what will happen after death. This profound confusion over life's purpose highlights our human limitations [ביאור שטיינזלץ]. Yet, the primary approach among commentators is to view this uncertainty not as a cause for despair, but as a direct call to spiritual action. The challenge is to become the wise individual who knows exactly which good deeds to perform during this short existence in order to merit a long life in the World to Come [רש״י, חומת אנך, צאינה וראינה]. Because the physical world is temporary and lacks lasting substance, the only true good worth holding onto is the study of Torah and the fulfillment of Commandments [תורה תמימה]. Unfortunately, very few people truly grasp what this genuine good is [מצודת דוד]. Instead, many become distracted by material pursuits, completely unaware if the wealth they chase will actually benefit them or ultimately lead to their downfall [אבן עזרא, תעלומות חכמה].
Because our days are numbered, few, and lacking physical permanence, a critical question arises regarding how we should treat the time we have left. The comparison of human life to a shadow offers two distinct paths of thought. The first approach emphasizes speed and the maximum use of time. Knowing that life passes swiftly, a person must hurry to perform good deeds. This passing life is not like the fixed shadow of a wall or a palm tree, but rather like the shadow of a flying bird that vanishes in the blink of an eye [רש״י, תורה תמימה]. Just as a shadow constantly shifts with the movement of the sun and never rests, a person must act continuously and without pause [מצודת דוד]. The second approach calls for a profound shift in perception. Rather than simply rushing, one should view all worldly matters and physical pleasures as a passing, unimportant shadow. Understanding the physical world in this way makes it much easier to step away from material desires and focus entirely on eternal, spiritual joy [אבן עזרא, תעלומות חכמה].
This fleeting existence is further complicated by our helplessness regarding the future. The inability to know what will happen after we are gone serves as a strong warning against the blind pursuit of money. People often exhaust themselves, and sometimes even exploit others, to gather wealth to leave to their children. However, since there is absolutely no way to know what will happen to this property after death, wasting one's life energy on such pursuits is pointless [רש״י, אבן עזרא, חומת אנך, צאינה וראינה, תעלומות חכמה]. Human ignorance is so deep that a person does not even know what is happening directly behind their own back in the physical world unless someone tells them, let alone what will occur in the distant future [מצודת דוד]. This total inability to predict what will survive after death makes it incredibly difficult to know what good is actually worth doing [ביאור שטיינזלץ]. Yet, the solution to this confusion lies in the realization that the only thing that certainly remains after a person passes away, and the greatest good of all, is the good name they have earned through their actions [תורה תמימה].