As one can see from most modern translations, the Book of Psalms is divided into five books. Psalm 72 is the last psalm in the second book. It is not entirely clear why there are five books. One suggestion is that the entire book was put together in five stages. No-one knows who the individuals were who arranged the psalms in the order that we have them. Of course, we don’t need to know who they were; all that matters is that we know God was supervising the composing of each psalm and the process of putting the Psalter into its current arrangement.
The heading of Psalm 72 indicates it was composed as a prayer by Solomon. In the psalm Solomon indicates what his priorities should be, as under his rule the kingdom of Israel expands. It is obvious that Solomon wanted to rule justly and ensure peace. This explains why he asks that people will pray for him (v. 15).
Yet it is clear from the contents of the psalm that Solomon has another of his descendants in mind as well. However great Solomon’s kingdom would become, it would not be the final or the climactic version of the Davidic kingdom. That final version would be in place when the Messiah, the ultimate Son of David, would reign.
The psalm mentions several factors of the reign of the Messiah that go beyond the achievements of Solomon. In particular, the psalm indicates that the Messiah’s kingdom, once it began, would last throughout all the generations of time (v. 5). Further, the Messiah’s kingdom would extend beyond the limits of Solomon’s kingdom to the ends of the earth – in verse 8 the Messiah’s kingdom would move out from the River (the Euphrates) to the ends of the earth (also verse 19). The point of this geographical description is that Solomon’s kingdom stopped at the Euphrates and went no further. These historical and geographical dimensions of the Messiah’s kingdom began when Jesus sat on the throne of God after his ascension. We know that his kingdom will last until he returns and that it will keep on extending until then as well.
The psalm also indicates that the Messiah will have far more subjects than Solomon. It is true that Solomon conquered other nations, but he did not rule over the ones mentioned in verse 10 and 11. These far off kings and kingdoms are examples of those who, from the ends of the earth, would bow to the Messiah. Others whom Solomon could not conquer, such as the independent desert tribes (v. 9), picture more types who will yet bow to the Messiah. In fact, says David, all nations eventually will bow before the Messiah (v. 11) and call him blessed (v. 17).
The reign of the Messiah would also produce benefits that Solomon could not provide. A remarkable picture is given in verse 16 of corn growing in abundance on the tops of the mountains, which was a place where corn did not usually grow at all. This is a picture of the Messiah’s ability to turn desolate places into locations of flourishing harvests (in a spiritual sense).
It is not surprising to note that Solomon, as he anticipated the reign of the Messiah, wanted to bless God for his wonderful works and to look ahead to the time when his glory would be known throughout the earth (vv. 18-19). Of course, we live in the days when the psalm is being fulfilled.