Human existence in this world is fleeting and finite, characterized by struggles that highlight the insignificance of the physical against the backdrop of eternity. This brevity is not merely a biological fact, but a lens through which people must evaluate their achievements against the limited time they possess. The standard human lifespan is generally recognized as seventy years. However, a question arises regarding the author of this prayer, Moses, who lived to be one hundred and twenty. The primary approach among commentators is that Moses spoke prophetically about future generations, particularly those living in exile with shorter lifespans who desperately yearn for redemption [רד״ק, אבן עזרא, מאירי]. Alternatively, Moses may have composed this prayer when he himself was exactly eighty years old [אבן עזרא]. Reaching this age of eighty is possible if a person possesses an exceptionally strong and overpowering physical constitution [מצודת דוד, מאירי].
This strict limitation on human life serves to humble human pride. For example, a heavenly voice once reminded the wicked Nebuchadnezzar, who arrogantly sought to elevate himself to the heavens, that his entire existence amounted to a mere seventy or eighty years, a tiny fraction compared to the incomprehensible vastness of creation [תורה תמימה]. Furthermore, living a long life does not grant immunity from God's strict justice. Even when a life concludes at an advanced age, it can still be a manifestation of hidden divine punishment [חומת אנך].
Beyond the sheer limits of time, the quality of these years is deeply complex. The prime periods of life, characterized by strength, greatness, power, and success [רד״ק, מלבי״ם, מצודת ציון], are ultimately defined by empty toil and sin. People become so consumed by a pointless race after worldly matters that they are left without the time or energy to repent and engage in what is genuinely meaningful [ביאור שטיינזלץ]. The realization that vitality and youth cannot last forever only adds deeper sorrow and pain when that strength inevitably fades [מצודת דוד].
The conclusion of life arrives with startling speed. Time rushes forward [מלבי״ם], and life is swiftly cut off and removed [רש״י, מצודת ציון, רד״ק]. Humanity flies away toward the grave as quickly as a migrating bird [רד״ק, אבן עזרא], passing in the blink of an eye or vanishing into the shadows of death [אבן עזרא]. This rapid, fleeting existence offers a profound perspective on the suffering of the righteous and the prosperity of the wicked. While the wicked may endure long lives filled with empty toil, a righteous person who dies young has simply rushed to complete their spiritual purpose in a short time. God gathers them early to protect them from future sin and corruption. This reality, where the righteous pass away prematurely while the wicked live on, leaves humanity in darkness and confusion, struggling to comprehend God's hidden and wondrous ways [אלשיך].