Albert Barnes Commentary Psalms 2:8

"Ask of me, and I will give [thee] the nations for thine inheritance, And the uttermost parts of the earth for thy possession." — Psalms 2:8 (ASV)

Ask of me - That is, of God. This is a part of the “decree” or purpose, as mentioned in Psalms 2:7. That decree embraced not only the design to constitute him as his Son, in the sense that he was to be king in Zion, but also the purpose to give him a dominion embracing the heathen and the uttermost parts of the earth. This wide dominion was to be given him on condition that he would “ask” for it, thus keeping up the idea that Yahweh, as such, is the great source of authority and empire, and that the Messiah, as such, occupies a rank subordinate to him. This relation of the Father and Son is everywhere recognized in the New Testament. As we may be sure that the Messiah will ask for this, it follows that the world will yet be brought under his scepter.

It may be added that as this wide dominion is promised to the Messiah only on condition that he “asks” for it or prays for it, much more is it true that we can hope for this and for no favor from God, unless we seek it by earnest prayer.

And I shall give you - I will give you. That is, he would ultimately give him this possession. No time is specified when it would be done, and the prophecy will be fulfilled if it is accomplished in any period of the history of the world.

The heathen - The nations (see notes on Psalms 2:1); that is, the world. In the time of the writer of the psalm, the world would be spoken of as divided into Hebrews and other nations—the people of God and foreigners. The same division is often referred to in the New Testament under the terms Jew and Gentile, as the Greeks divided all the world into Greeks and barbarians. The word would now embrace all the nations that are not under the influence of the true religion.

For your inheritance - Your heritage; your portion as my Son. There is an allusion here to the fact that he had constituted him as his Son, and hence, it was proper to speak of him as the heir of all things. (See the notes on Hebrews 1:4).

And the uttermost parts of the earth - The farthest regions of the world. This promise would properly embrace all the world as then known, as it is now known, and as it will be known in the future.

For your possession - That is, as king. This, on the earth, was to be his possession as the Son of Yahweh, constituted as king. It may be remarked here:

1. That this can have its fulfillment only in the Lord Jesus Christ. It was not true of David nor of any other Hebrew monarch that any such possession had, in fact, been conceded to him. Their dominions extended, at any time, little beyond the bounds of Palestine and embraced a very limited part of the earth—but a small territory, even as compared with many then existing kingdoms. The phrase used here could never have been applied to the limited and narrow country of Palestine.
2. The promise is to be understood as still in full force. It has never been canceled or recalled, and though its fulfillment has seemed to be long delayed, yet as no time was specified, its spirit and meaning have not been disregarded. Events have shown that it was not intended that it should be speedily accomplished; and events, when no time is specified, should be allowed to be interpreters of the original meaning of the prophecy.
3. The promise will yet be fulfilled. It is evidently supposed in the promise that the Messiah would ask for this; and it is solemnly affirmed that if he did, this wide inheritance would be granted to him. The world, then, is to be regarded as given by covenant to the Son of God, and in due time he will set up his dominion over the earth and rule over mankind. The period is coming when the actual scepter that sways over the nations of the earth will be that of the Son of God, and when his right to give laws and to reign will be acknowledged from the rising to the setting sun. This is the only thing in the future that is certainly known to us, and this is enough to make everything in that future bright.