The answer is: Psalm 90

Psalm 90 - This psalm, attributed to Moses, reflects on the brevity of human life and God’s eternal nature. It contrasts the fleeting existence of man with God’s everlasting presence. Interestingly, it serves as a lament but also calls for wisdom (90:12), paralleling themes found in Ecclesiastes regarding the meaning of life.

Psalm 90, famously known as "A Prayer of Moses," is a poignant reflection on human temporality set against the backdrop of God's timeless nature. This unique attribution is noteworthy because it makes Moses the only figure in the Hebrew Bible to have a psalm explicitly credited to him—quite a distinction! Unlike many psalms that celebrate divine acts or victory, Psalm 90 takes a different tone, offering profound insights on mortality.

As you read through this psalm, you might notice echoes of existential themes found elsewhere in Scripture. For instance, the pursuit of meaning found in Ecclesiastes—“vanity of vanities” in chapter 1—aligns beautifully with Moses' call for wisdom in verse 12. Both works plead for awareness of life's fleeting nature. Additionally, Moses being the chosen leader guiding the Israelites through the wilderness could evoke sentiments of longing for stability against the harsh journey of life, neatly tying into the longing expressed within this prayer.

Trivia time: Did you know that Psalm 90 is also believed to be the inspiration behind the famous phrase "The days of our years are threescore years and ten," from Psalm 90:10? This claim to a typical lifespan has shaped conceptions of age and wisdom in many cultures, making Moses’ contemplations relevant far beyond his time.

So, whether reflecting on a personal journey or the humbling course of humanity itself, Psalm 90 resonates deeply—it shows us that in recognizing our limitations, we may just crack open the door to understanding the infinite.