Today is the feast of Christ the King in the Extraordinary Form (in the Novus Ordo it is celebrated on the last Sunday before Advent, a date that has a certain logic to it).
There is of course something of an embarrassment of choices when it comes to potential propers for a (relatively recent) feast of this kind, and so the Introit comes from Revelation, and the Alleluia verse from the book of Daniel. Three psalms are used however: Psalm 2 (Offertory); Psalm 28 (Communio); and Psalm 71 (Introit verse and Gradual).
As Psalm 71 is one of the key psalms prophesying the kingdom, it is worth setting out in full, first the Vulgate, then the Douay-Rheims (I've bolded the verses used in the propers for today):
Deus, judicium tuum regi da, et justitiam tuam filio regis; judicare populum tuum in justitia, et pauperes tuos in judicio.
3 Suscipiant montes pacem populo, et colles justitiam.
4 Judicabit pauperes populi, et salvos faciet filios pauperum, et humiliabit calumniatorem.
5 Et permanebit cum sole, et ante lunam, in generatione et generationem.
6 Descendet sicut pluvia in vellus, et sicut stillicidia stillantia super terram.
7 Orietur in diebus ejus justitia, et abundantia pacis, donec auferatur luna.
8 Et dominabitur a mari usque ad mare, et a flumine usque ad terminos orbis terrarum.
9 Coram illo procident Æthiopes, et inimici ejus terram lingent.
10 Reges Tharsis et insulæ munera offerent; reges Arabum et Saba dona adducent:
11 et adorabunt eum omnes reges terræ; omnes gentes servient ei.
12 Quia liberabit pauperem a potente, et pauperem cui non erat adjutor.
13 Parcet pauperi et inopi, et animas pauperum salvas faciet.
14 Ex usuris et iniquitate redimet animas eorum, et honorabile nomen eorum coram illo.
15 Et vivet, et dabitur ei de auro Arabiæ; et adorabunt de ipso semper, tota die benedicent ei.
16 Et erit firmamentum in terra in summis montium; superextolletur super Libanum fructus ejus, et florebunt de civitate sicut fœnum terræ.
17 Sit nomen ejus benedictum in sæcula; ante solem permanet nomen ejus. Et benedicentur in ipso omnes tribus terræ; omnes gentes magnificabunt eum.
18 Benedictus Dominus Deus Israël, qui facit mirabilia solus.
19 Et benedictum nomen majestatis ejus in æternum, et replebitur majestate ejus omnis terra. Fiat, fiat.
Give to the king your judgment, O God, and to the king's son your justice:
To judge your people with justice, and your poor with judgment.
3 Let the mountains receive peace for the people: and the hills justice.
4 He shall judge the poor of the people, and he shall save the children of the poor: and he shall humble the oppressor.
5 And he shall continue with the sun and before the moon, throughout all generations.
6 He shall come down like rain upon the fleece; and as showers falling gently upon the earth.
7 In his days shall justice spring up, and abundance of peace, till the moon be taken away.
8 And he shall rule from sea to sea, and from the river unto the ends of the earth.
9 Before him the Ethiopians shall fall down: and his enemies shall lick the ground.
10 The kings of Tharsis and the islands shall offer presents: the kings of the Arabians and of Saba shall bring gifts:
11 And all kings of the earth shall adore him: all nations shall serve him.
12 For he shall deliver the poor from the mighty: and the needy that had no helper.
13 He shall spare the poor and needy: and he shall save the souls of the poor.
14 He shall redeem their souls from usuries and iniquity: and their names shall be honourable in his sight.
15 And he shall live, and to him shall be given of the gold of Arabia, for him they shall always adore: they shall bless him all the day.
16 And there shall be a firmament on the earth on the tops of mountains, above Libanus shall the fruit thereof be exalted: and they of the city shall flourish like the grass of the earth.
17 Let his name be blessed for evermore: his name continues before the sun.
And in him shall all the tribes of the earth be blessed: all nations shall magnify him.
18 Blessed be the Lord, the God of Israel, who alone does wonderful things.
19 And blessed be the name of his majesty for ever: and the whole earth shall be filled with his majesty. So be it. So be it.