Discerning a progressive Christian perspective on some Old Testament texts can be as challenging as it is for literalists to graft “history” onto every metaphorical story in the Bible.
This psalm is a case in point. As John Shearman notes in his commentary for Epiphany, it’s a hymn that would have been sung for the coronation of a new king. Which makes it, obliquely, appropriate as a reference to how the early church founders envisioned the “reign of Christ.”
However, if we can get past the whole kingship and ruler imagery, I think that this excerpt still has meaning for us today.
Rain on mown grass and abounding peace say more about the fostering of our agapé relationship with each other and Creation than they do about any conquering monarch.
In that sense, may the Message of the Christ indeed live in each of us until the “moon is no more.”
May he live while the sun endures, and as long as the moon, throughout all generations. May he be like rain that falls on the mown grass, like showers that water the earth. In his days may righteousness flourish and peace abound, until the moon is no more. Psalm 72: 5-7