A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
psa 47:1Praise is given to God for victory, perhaps that recorded (Ch2 20:20-30); and His dominions over all people, Jews and Gentiles, is asserted. (Psa 47:1-9)
clap . . . hands . . . people--literally, "peoples," or "nations" (compare Deu 32:43; Psa 18:49; Psa 98:9).
psa 47:2His universal sovereignty now exists, and will be made known.
psa 47:3under us--that is, His saints; Israel's temporal victories were types of the spiritual conquests of the true Church.
psa 47:4He shall . . . inheritance--the heathen to be possessed by His Church (Psa 2:8), as Canaan by the Jews.
excellency of Jacob--literally, "pride," or, that in which he glories (not necessarily, though often, in a bad sense), the privileges of the chosen people--
whom he loved--His love being the sole cause of granting them.
psa 47:5God, victorious over His enemies, reascends to heaven, amid the triumphant praises of His people, who celebrate His sovereign dominion. This sovereignty is what the Psalm teaches; hence he adds,
sing . . . praises with understanding--literally, "sing and play an instructive (Psalm)." The whole typifies Christ's ascension (compare Psa 68:18).
psa 47:8The instruction continued.
throne of . . . holiness--or, "holy throne" (see on Psa 2:6; Psa 23:4).
psa 47:9princes--who represent peoples. For--
even--supply, "as," or, "to"--that is, they all become united under covenant with Abraham's God.
shields--as in Hos 4:18, "rulers" [Margin].