Having looked at the psalmists first two reasons for praise, that God is the great king over all the earth, and that he is the one who is subduing his enemies and reigning over all the nations. We turn now to the third reason to praise God, because he chose our heritage for us, the pride of Jacob whom he loves, and the princes of the peoples gather as the people of the God of Abraham, for the shields of the earth belong to God; he is highly exalted.
Again as in the last point there two verses 4 and 9 follow along with the psalmist close connection between the initiation and the subsequent consummation. The Jew had much to rejoice about, and it's clear that one of those things is the seeming chance by which they were born to a Jewish family. Some people in this world look upon the race, or social status or the family they were born to as simply chance, But our God who is the king over all of creation, who knows the hairs on your head determined who your parents would be. So when this psalm was written to be born a Jew meant you were entitled to the inheritance of Jacob. We read what God blessed Jacob within Genesis 35:9-12 God appeared to Jacob again when he came from padded-arm and blessed him. And God said to him 'Your name is Jacob; no longer shall your name be called Jacob, but Israel shall be your name. So he called his name Israel. And God said to him, "I am God Almighty, be fruitful and multiply. A nation and a company of nations shall come from you, and kings shall come from your own body. The land that I gave to Abraham and Isaac, I will give to you, and I will give the land to your offspring after you. Also, we could look to when Jacob was blessed by his father, in Genesis 28 when he says May he give the blessing of Abraham to you and to your offspring with you, that you may take possession of the land of your sojourning that God gave to Abraham.
The way in which blessing and inheritance worked in the Old Testament is that the one who received the blessing would have the right to distribute the blessing to his lineage. It the old testament this was determined by lineage, which is why there is a huge importance to genealogies. But what the psalmist is recognizing is that the blessing these Jews received, the right to live in the land flowing with milk and honey did not come from their own merit, rather God chose Jacob to have the blessing, and God chose them to be his descendants. And it these people who in the Old Testament were to come together and gather before the God of Abraham, recognizing that he their political and military sovereign. To turn their allegiance to anyone else to celebrate the victory of anyone else would be gross misconduct which would cause you to lose your right to the inheritance.
Now you may ask how is it that we can sing this, unless your Jewish, how is Jacob your father, or even Abraham. Galatians 3:7 makes that relationship clear for us. Abraham was promised a son who would extend a blessing and an inheritance to all the nations. Galatians 3:9 says so then those who are of faith are blessed along with Abraham, the man of faith. Those who have faith receive through Christ the blessing which he merited by his perfect obedience. The people of Israel rejoiced and sang this verse in the psalm because they felt fortunate by God to have privileged access to the land and the right to gather there before God, we sing because we have a much greater blessing, the blessing that comes by faith. Those who have apprehended Christ by faith are the true children of God, and we gather together here on Sunday to worship and sing praise to God, and in the consummation we will all gather with all the saints in the New Heavens and earth as it says Revelation 21:5 And he who was seated on the throne, Behold I am making all things new, words are trustworthy and true. And he said to me. It is done! I am the Alpha and the Omega, the beginning and the end. To the thirsty I will give from the spring of the water of life without payment. The one who conquers will have this heritage and I will be his God and he will be my son. And he continues in Revelation 22:3-5 No longer will there be anything accursed, but the throne of God and of the lamb will be in it, and his servants will worship him. They will see his face, and his name will be on their foreheads, and the night will no more, they will need no light of lamp or sun for the Lord God will be their light and they will reign forever and ever.
Those who reign forever and ever are those who worship, the princes who gather together, who even now having the down payment of this inheritance in the indwelling holy spirit can rejoice that God chose use to be born again to have this heritage in Christ which was also had by the saints of old by the very same faith.