John Calvin Commentary Psalms 47:7

"For God is the King of all the earth: Sing ye praises with understanding." — Psalms 47:7 (ASV)

For God is King of all the earth. The Psalmist, having called God at the end of the preceding verse King of the chosen people, now calls him King of all the earth; and thus, while he claims for the Jews the right and honor of primogeniture, he at the same time joins to them the Gentiles as associates and partakers with them of the same blessing.

By these words he indicates that the kingdom of God would be much more magnificent and glorious at the coming of the Messiah than it was under the shadowy dispensation of the Law, since it would be extended to the utmost boundaries of the earth. To show the greater earnestness in his exhortation, he repeats the words, Sing praises to God, five times.

The word מםכיל, maskil, is used in the singular instead of the plural, for he invites to this exercise all who are skillful in singing. He, no doubt, refers to knowledge in the art of music.

But he requires, at the same time, that the worshippers of God sing the praises of God intelligently, so that there is not the mere sound of tongues, as we know to be the case among the Papists. Knowledge of what is sung is required to engage properly in singing psalms, so that the name of God may not be profaned—as it certainly would be, if there were nothing more than the voice, which melts away or is dissolved in the air.