C. F. Keil and Franz Delitzsch on Psalms 82:8

Psa 82:8

The poet closes with the prayer for the realization of that which he has beheld in spirit. He implored God Himself to sit in judgment (שׁפטה as in Lam 3:59), since judgment is so badly exercised upon the earth. All peoples are indeed His נחלה, He has an hereditary and proprietary right among (lxx and Vulgate according to Num 18:20, and frequently), or rather in (בּ as in משׁל בּ, instead of the accusative of the object, Zec 2:11), all nations (ἔθνη) - may He then be pleased to maintain it judicially. The inference drawn from this point backwards, that the Psalm is directed against the possessors of power among the Gentiles, is erroneous. Israel itself, in so far as it acts inconsistently with its theocratic character, belies its sanctified nationality, is a גוי like the גוים, and is put into the same category with these. The judgment over the world is also a judgment over the Israel that is become conformed to the world, and its God-estranged chiefs.