Charles H. Spurgeon on Psalms 67:4

For thou shalt judge the people righteously, etc. The Psalmist may here seem to contradict himself; for if mercy make men rejoice, then judgment occasions men to tremble. Answer is made, that all such as have known the ways of the Lord, and rejoice in the strength of his salvation, all such as have the pardon of their sins assured and sealed, fear not that dreadful assize, because they know the judge is their advocate. Or, (as Jerome,)let all nations rejoice, because God doth judge righteously, being the God of the Gentiles as well as of the Jews. Ac 10:34. Or, let all nations rejoice, because God doth govern all nations; that whereas theretofore they wandered in the fond imaginations of their own hearts, in wry ways, in byways; now they are directed by the Spirit of truth to walk in God's highway, which leads unto the celestial Jerusalem; now they shall know Christ, the way, the truth, and the life. For judging is often used for ruling. 1Sa 7:15 2Co 1:10. So David doth here expound himself: thou shalt judge. that is, thou shalt govern the nations. John Boys.