Sing to the LORD a new song;
sing to the LORD, all you lands.
Sing to the LORD; bless his name;
announce his salvation, day after day.
Let the heavens be glad and the earth rejoice;
let the sea and what fills it resound;
let the plains be joyful and all that is in them!
Then shall all the trees of the forest exult before the LORD.
The LORD comes,
he comes to rule the earth.
He shall rule the world with justice
and the peoples with his constancy.
(Psalm 96:1-2, 11-13)
96:1–3. “A new song” (cf. Ps 33:3; 40:3; Is 42:10) may refer to the fact that this is a newly composed psalm, or to the new situation implied by the belief that the nations will worship the God of Israel (vv. 3, 7, 10).
96:10–13. The peoples are also invited to acknowledge to each other that the God who controls the universe is also he who dispenses justice (v. 10). Hope that God will “judge the peoples with equity”, that is, by causing evil to disappear and by keeping his promises right across the world, leads the psalmist to invite all creation, even inanimate things, to rejoice (vv. 11–13): “What do this justice and fidelity mean? On the day of Judgment, he will gather his chosen ones to himself and send the rest away; he will place some to his right hand, and others to his left. It is only right and fair that those who show no mercy before the coming of the judge should not then hope for mercy from him. Whereas those who struggle to be merciful towards others will be judged with mercy” (St Augustine, Enarrationes in Psalmos, 95, 15).
When verse 13 says “he comes to rule the earth,” to what does it refer? According to I Chronicles 16:23–33, Psalm 96 is one of the hymns of praise sung by Asaph and his choral guild before the ark after David brought it to Jerusalem. The procession bringing the ark of the LORD represented in liturgical drama his coming to his palace-temple as king (see Ps. 24:7–10). The reality behind the liturgical act was the marvelous works of salvation, the historical occasions when Israel had experienced the intervention of the LORD, moments Israel remembered in epic story (Exodus, Joshua, Judges, Samuel) and in poetry celebrating the LORD’s coming in theophany (Psalm 18; note the repetition of Ps. 29:1–2 in 98:7–9). Phrases and clauses from Psalm 96 and from Psalms 97 and 98 appear in the prophecy of the exilic Isaiah (compare vv. 11–13 with Isa. 40:10; 44:23; 49:13; 55:12; also 59:19f.; 60:1; 62:11). Isaiah saw the return of the exiles from Babylon as a revelation of the LORD as king and as a demonstration of his rule that proved that the gods of the nations were nothing.
The past “comings” of the LORD have a future. The liturgy remembers and anticipates. The psalm always places those who sing it in the presence of the LORD who has come and will rule the earth in righteousness and faithfulness. The hymn looks back to the nativity and forward to the second coming; Christ has come, and will come again. The psalm puts the Christ event in the sequence of the Old Testament marvelous works by which the LORD manifested his rule. It interprets the Christ as the LORD’s demonstration that other gods are mere nothings. Through the Christ, the LORD is working out his rule of righteousness and faithfulness among the nations.
– James Mays
May the virtues of faith, hope, and love go with you today – DV.
 James Gavigan, Brian McCarthy, and Thomas McGovern, eds., Psalms and the Song of Solomon, The Navarre Bible (Dublin; New York: Four Courts Press; Scepter Publishers, 2003), 323–325.