Thou art more glorious and excellent - The word rendered glorious - נאור na'ôr - is from the verb which means "to shine," to give light, and the word would properly refer to a luminous or "shining" object - as the sun, the source of light. Hence, it means "shining," splendid, glorious; and it is thus applied to the Divine Being with reference to his perfections, being like light. Compare 1-John 1:5. The word rendered "excellent," means exalted, noble, great. These words are applied here to God from the manifestation of his perfections in the case referred to.
Than the mountains of prey - The word "prey" as employed here - טרף ṭereph - means that which is obtained by hunting; and then, plunder. It is usually applied to the food of wild beasts, beasts of prey. Here it refers to the "mountains" considered as the abode or stronghold of robbers and banditti, from where they sally forth in search of plunder. These mountains, in their heights, their rocks, their fastnesses, furnished safe places of retreat for robbers, and hence, they became emblems of power. It is not improbable that the hordes referred to in the psalm had their abodes in such mountains, and hence, the psalmist says that God who made those mountains and hills was superior to them in strength and power.

Than the mountains of prey - This is an address to Mount Zion. Thou art more illustrious and excellent than all the mountains of prey, i.e., where wild beasts wander, and prey on those that are more helpless than themselves. Zion was the place where God dwelt; the other mountains were the abode of wild beasts.

Thou [art] more glorious [and] excellent than (c) the mountains of prey.
(c) He compares the kingdom full of extortion and rapine to the mountains that are full of ravening beasts.

Thou art more glorious and excellent than the mountains of prey. Which is to be understood not of Zion, as some interpret it; though it is true that the mountain of Zion, or the church of Christ, his kingdom and interest, shall in the latter day be more glorious and excellent than all other mountains, kingdoms, and interests; see Isaiah 2:2, but of God or Christ before spoken of; and so the Targum,
"bright, to be feared, art thou, O God, to be praised from the house of thy sanctuary.''
Christ, who is God over all, is "bright" (z), splendid, and glorious, in his divine nature, being the brightness of his Father's glory, and the express image of his person: and "excellent" in his office as Mediator, and in all his works as such; and in human nature, at he is exalted at his Father's right hand, far above all principality, power, might, and dominion, signified here by "mountains of prey": the kingdoms of this world, because of their eminence and strength, are compared to mountains: see Isaiah 41:15 and may be called "mountains of prey", in allusion to mountains inhabited by beasts of prey, as lions and leopards; see Song 4:8 because obtained and possessed by tyranny and oppression. Christ is more glorious and excellent than the kings of the earth; he is higher than they, and is King of kings; he is richer than they, the earth is the Lord's, and the fulness thereof, the world, and they that dwell therein; he is wiser than they, by him kings reign, and princes decree justice; he is more powerful than they, and all must submit to him, and all will serve him hereafter; and his kingdom will be greater than theirs, more large and more lasting; it will be an everlasting one, and reach from sea to sea, and even to the ends of the earth.
(z) "illustris", Pagninus, Montanus, Musculus, Junius & Tremellius, Piscator; "illustrior", Tigurine, version; "splendidus", Vatablus, Gejerus, Michaelis; "bright", Ainsworth.

Thou--God.
mountains of prey--great victorious nations, as Assyria (Isaiah 41:15; Ezekiel 38:11-12; Zac 4:7).

The "mountains of prey," for which the lxx has ὀρέων αἰωνίων (טרם?), is an emblematical appellation for the haughty possessors of power who also plunder every one that comes near them,
(Note: One verse of a beautiful poem of the Muḥammel which Ibn Dûchı̂, the phylarch of the Beni Zumeir, an honoured poet of the steppe, dictated to Consul Wetzstein runs thus: The noble are like a very lofty hill-side upon which, when thou comest to it, thou findest an evening meal and protection (Arab. 'l-‛š' w-ḏry).)
or the proud and despoiling worldly powers. Far aloft beyond these towers the glory of God. He is נאור, illustris, prop. illumined; said of God: light-encircled, fortified in light, in the sense of Daniel 2:22; 1-Timothy 6:16. He is the אדּיר, to whom the Lebanon of the hostile army of the nations must succumb (Isaiah 10:34) According to Solinus (ed. Mommsen, p. 124) the Moors call Atlas Addirim. This succumbing is described in Psalm 76:6. The strong of heart or stout-hearted, the lion-hearted, have been despoiled, disarmed, exuti; אשׁתּוללוּ
(Note: With orthophonic Gaja, vid., Baer's Metheg-Setzung, 45.)
is an Aramaizing praet. Hithpo. (like אתחבּר, 2-Chronicles 20:35, cf. Daniel 4:16; Isaiah 63:3) with a passive signification. From Psalm 76:6 we see that the beginning of the catastrophe is described, and therefore נמוּ (perhaps on that account accented on the ult.) is meant inchoatively: they have fallen into their sleep, viz., the eternal sleep (Jeremiah 51:39, Jeremiah 51:57), as Nahum says (Nahum 3:18): thy shepherds sleep, O king of Assyria, thy valiant ones rest. In Psalm 76:6 we see them lying in the last throes of death, and making a last effort to spring up again. But they cannot find their hands, which they have lifted up threateningly against Jerusalem: these are lamed, motionless, rigid and dead; cf. the phrases in Joshua 8:20; 2-Samuel 7:27, and the Talmudic phrase, "he did not find his hands and feet in the school-house," i.e., he was entirely disconcerted and stupefied.
(Note: Dukes, Rabbinische Blumenlese, S. 191.)
This field of corpses is the effect of the omnipotent energy of the word of the God of Jacob; cf. וגער בּו, Isaiah 17:13. Before His threatening both war-chariot and horse (ו - ו) are sunk into motionlessness and unconsciousness - an allusion to Ex. 15, as in Isaiah 43:17 : who bringeth out chariot and horse, army and heroes - together they faint away, they shall never rise; they have flickered out, like a wick they are extinguished.

Thou - O God. Than - The greatest kings and empires of the earth, which in prophetic writings are often compared to mountains. And they are called mountains of prey, because they generally were established by tyranny, and maintained by preying upon their own subjects, or other kingdoms.