The answer is: A prophecy of the future kingdom after the return of Christ

Psalm 72 - Often viewed as a messianic psalm, it describes the ideal reign of a righteous king whose rule brings justice and peace. This vision aligns with prophecies in Isaiah (Isaiah 9:6-7) about the coming Messiah, emphasizing God's ultimate plan for restoration and unity through Christ.

Psalm 72 is a beautiful song, often seen as a longing for ideal governance - a king whose rule embodies justice, righteousness, and peace. When this psalm is examined, it paints a lush picture of a world transformed; mountains and hills rejoicing because justice has arrived. In Biblical times, kings were seen as God's representatives. Thus, a ruling figure embodying these virtuous traits holds profound significance.

Interestingly, this psalm reminds us of similar themes found not only in the rest of the Psalms but also in the prophets like Isaiah and Micah. For instance, in Micah 4:3, we hear of swords being turned into plowshares, symbolizing peace triumphing over conflict. Psalms like 46 even echo this theme, declaring, "Be still and know that I am God," highlighting a divine invite into a serene understanding of a peaceful world.

You can’t help but smile thinking of this ideal. We see references to creatures, possibly even dragons, pondering prophetic references to divine harmony in Isaiah contextualizing God's cosmic order—a sign that even creation participates in promoting this peace.

Interestingly, some ancient cultures also longed for their rulers to promote fairness and welfare, providing insight on whether psalmists drew influence from their surrounding societies. Still, the ambition remains purely centered on justice flowing like water. Psalms 72 teaches that longing for a better world starts here—with a desire for a king who leads with love, understanding, and justice.