Albert Barnes Commentary Psalms 72:20

"The prayers of David the son of Jesse are ended. BOOK III" — Psalms 72:20 (ASV)

The prayers of David the son of Jesse are ended. This statement is not found in the Syriac version. In that version, the following is added at the close of the psalm: “The end of the Second Book.” Regarding this twentieth verse, it is quite clear that it is not part of the psalm. It is also highly probable that it was not placed here by the psalm's author and that it has no special and exclusive reference to this particular psalm, as this psalm could not, in any special sense, be called “a prayer of David.”

The words bear all the marks of having been placed at the end of a collection of psalms, or a division of the Book of Psalms, which could appropriately have been titled “The Prayers of David, the son of Jesse.” This would mean that that book, or that division, consisted of David’s compositions and could thus be distinguished from other parts of the general collection.

This would not imply that this part of the collection contained literally no psalms other than those composed by David, or that none of David’s psalms could be found in other parts of the general collection. Rather, it would mean that this division was more completely made up of his psalms, and so the name could therefore be given to it as his collection.

From this, it may be fairly inferred that there was such a collection, or that there were divisions in the Book of Psalms that were recognized early on. See the General Introduction.

Dr. Horsley, however, supposes that this declaration, “The prayers of David the son of Jesse are ended,” pertains to this psalm alone. He suggests it is as if David had nothing more to pray for or to wish than what was expressed in these glowing representations of the Messiah’s kingdom and the happy times that would be enjoyed under his rule.