Poole on Revelation 7:15, 16: The Blessedness of Heaven, Part 1
Verse 15:[1] Therefore are they before the throne of God, and serve him day and night in his temple: and he that sitteth on the throne shall (Is. 4:5, 6; Rev. 21:3) dwell among them.
[Therefore] That is, because they washed, etc. (Cluverus, Durham).

[They are before the Throne of God] That is, adorned with heavenly glory, they serve God (Cluverus), enjoying a clear and continuous Vision of God and intimate familiarity (Tirinus, similarly Pareus, Cluverus). They are in sight of God: they are of the greatest concern to Him (Grotius). Others: He teaches that the true Church is denoted here (Forbes). They have fellowship with God, begun in the Church through the instituted worship, perfected in the heavens, before the Throne of glory (Durham). Others: It is not treated here of the kingdom and state of glory, in which the Lamb does not administrate, 1 Corinthians 15:24, as He does here; but of the kingdom of grace, of the felicitous state of the Church now liberated from all the oppression and servitude of Antichrist or other open enemies, possessing an abundance of light and peace, which nevertheless he expresses here magnificently, after the fashion of the Prophets, as in Isaiah 25; 49; 60. And it is remarkable that men, accustomed to the ordinary style of Scripture, drew these things to another sense. But concerning this matter, see more things on Revelation 20-22 (Forbes).
[They serve Him (not, I say, do they sleep, nor are they idle there [Cluverus]) day and night (that is, perpetually [Menochius], continuously [Tirinus], without intermission [Cluverus, Durham], forever [Pareus]: A catachresis,[2] for in Revelation 21:25 there shall be no night there [Menochius]) in His temple] That is, in heaven (Piscator, Drusius, Menochius, thus Pareus, Durham). Objection: There is no Temple there, Revelation 21:22. Response: Namely, of timber, but the Temple there is God and the Lamb (Pareus, thus Ribera), and the entire city of the blessed, for in it God is always celebrated with great love and suitable praises (Ribera). The sense is the same as in Revelation 4:8 (Grotius), they worship Him day, etc., suppose as Priests. The custom of the Jews in proving and admitting Priests is regarded, who were judged by the Great Sanhedrin, and, if vice was found in them, they put on black garments, and so, going out, they departed; if they were free from vice, they put on white garments, and, having entered in, they ministered with the Priests their brethren. See on Revelation 6:11 (Mede’s Works 1113). The blessed need no Priest (Durham), [but] they themselves, as true priests of God, as it were, offer themselves to God, and sing the praises of God (Ribera). It is a similitude taken from the Levites or Priests (Grotius, Durham, similarly Ribera, Cluverus, Beza), of which some were always keeping vigil in the Temple (Grotius, similarly Beza, Cluverus). See 1 Chronicles 9:33 (Cluverus); Psalm 134:1 (Cluverus, Grotius, Beza). And it is a tacit consolation. Indeed, the Jewish Temple, which is nothing but timber, shall perish; but there shall be another Temple, standing firm, constructed of pious minds and pure bodies (Grotius).
Therefore are they before the throne of God; not that they by their sufferings have merited heaven, but because it pleaseth God of his free grace so to reward them; therefore it was said, not only that they were such as came out of tribulation, but that they had washed their garments in the blood of the Lamb, whose blood had paid the price of their salvation. And serve him day and night in his temple: by the temple, some understand the church in this life, but it is foreign to the true sense of the text; for John saw only their souls before the throne, their bodies were in their graves. By the temple is meant heaven, where God dwelleth, and is worshipped more gloriously and constantly than he was in the Jewish temple, or in any part of the militant church.

[He shall dwell, etc., σκηνώσει ἐπ᾽ αὐτούς] He shall overshadow (that is, cover as if by a shade [Piscator, thus Beza]) them (Piscator). He shall be to them in the place of a tabernacle: He shall protect them against heat and injuries. In this sense, שָׁכַן is used of the Cloud, Numbers 9:18,[3] 22,[4] and is translated σκιάζειν; and in Psalm 5:11, in the Greek it is κατασκηνώσεις,[5] in the Latin, which Jerome expressed in accordance with the Hebrew, proteges, thou shalt cover: where in the Hebrew תַּסֵךְ is from סָכַךְ, to overshadow, which elsewhere is wont to be translated by σκιάζειν, to overshadow, ἐπισκιάζειν, to throw a shadow over, συσκιάζειν, to shade quite over, likewise by σκεπᾶν, to cover, and ἐπισκεπᾶν, to cover over. The sense: Here in Pella God will keep them safe from all those evils, the greatest of which await the contumacious Jews (Grotius). Others: He shall dwell above them (Vulgate), or, with them: עַל/upon in the place of עִם/with, as elsewhere, men עַל נָשִׁים, with women: or, among them, so that ἐπὶ/upon might be in the place of ἐν/in (Drusius). The sense: He shall be near and familiarly known by them, and that constantly and fully. Granting that the word σκηνόω is used of the incarnate Christ in John 1:14,[6] it is applicable to the Church militant, in which God will reveal Himself, even indeed without interruption, that is, such an interruption as had been previously under Antichrist (Durham). The sense: It shall enjoy the eternal favor, grace, and glory of God (Pareus). It denotes here the singular, and very familiar (Cluverus), presence and protection of God (Cluverus, Tirinus), by which He, as it were, attends to them, by continually regarding them, and by communicating and exhibiting Himself and all things pertaining to Him to them (Tirinus).
And he that sitteth on the throne shall dwell among them; as God by his gracious presence dwelt in the Jewish temple, so God by his glorious presence shall dwell amongst his glorified saints.
Verse 16:[7] (Is. 49:10) They shall hunger no more, neither thirst any more; (Ps. 121:6; Rev. 21:4) neither shall the sun light on them, nor any heat.

[They shall not hunger, etc.] As in this life, Matthew 25:42; 1 Corinthians 4:11. Life and condition shall be different there (Cluverus). He alludes to athletes, who were often compelled to suffer thirst and hunger, to abide under the open heaven, to raise up heaps in the midst of the heat of the Sun, etc. But as victors, and discharged soldiers, they are bestowed with quiet; and, if they should need, they are fed at public expense (Tirinus). Hunger, thirst, heat denote here all the wants and hardships of this life (Pareus). Others: They shall have whence they might live, who were previously in the greatest want. See 2 Corinthians 11:27; Philippians 4:12 (Grotius). They shall be fed by the grace of God, etc. See Psalm 23; John 4:13; 6:27, etc. (Forbes). They shall enjoy public assemblies without impediment or persecution (Hammond).
[Neither, etc., οὐδὲ—καῦμα] Neither upon them shall fall the sun (that is, the heat of the Sun [Piscator]), neither any heat (Beza, Piscator). Whether from the Sun, or from a scorching wind, Jonah 4:8,[8] which the Greeks call καύσωνα, burning heat. These and the preceding words were taken from Isaiah 49:10, where in the Greek ὁ καύσων is put in the place of שָׁרָב, burning heat,[9] as elsewhere in the place of קָדִים/east, as in Ezekiel 17:10;[10] 19:12;[11] Hosea 12:1;[12] 13:15;[13] etc. (Grotius). Neither heat, whether corporal, Genesis 31:40;[14] Matthew 20:12;[15] or spiritual (Cluverus), namely, of persecution (Piscator), of affliction and temptation, of which things are used both καῦμα, Luke 8:13 (Cluverus); Matthew 13:6,[16] 21 (Cluverus, Piscator), and πύρωσις/burning, 1 Peter 4:12[17] (Cluverus). Others: [The sense:] They shall be free from inconveniences. For the Hebrews are wont to express all inconveniences by heat (Grotius).
They shall hunger no more, etc.: This is taken out of Isaiah 49:10. They are all metaphorical expressions, all signifying the perfect state of glorified saints; they shall have no wants, nor be exposed to any afflictive providences.
[1] Greek: διὰ τοῦτό εἰσιν ἐνώπιον τοῦ θρόνου τοῦ Θεοῦ, καὶ λατρεύουσιν αὐτῷ ἡμέρας καὶ νυκτὸς ἐν τῷ ναῷ αὐτοῦ· καὶ ὁ καθήμενος ἐπὶ τοῦ θρόνου σκηνώσει ἐπ᾽ αὐτούς. [2] A catachresis is an improper use of a word or words. [3] Numbers 9:18: “At the commandment of the Lord the children of Israel journeyed, and at the commandment of the Lord they pitched: as long as the cloud abode (יִשְׁכֹּן; σκιάζει, in the Septuagint) upon the tabernacle (הַמִּשְׁכָּן; τῆς σκηνῆς, in the Septuagint) they rested in their tents.” [4] Numbers 9:22: “Or whether it were two days, or a month, or a year, that the cloud tarried upon the tabernacle (הַמִּשְׁכָּן), to abide (לִשְׁכֹּן; σκιαζούσης, in the Septuagint) thereon, the children of Israel abode in their tents, and journeyed not: but when it was taken up, they journeyed.” [5] Psalm 5:11: “But let all those that put their trust in thee rejoice: let them ever shout for joy, because thou coverest (וְתָסֵךְ; κατασκηνώσεις, shalt dwell among, in the Septuagint) them: let them also that love thy name be joyful in thee.” [6] John 1:14: “And the Word was made flesh, and dwelt (ἐσκήνωσεν) among us, (and we beheld his glory, the glory as of the only begotten of the Father,) full of grace and truth.” [7] Greek: οὐ πεινάσουσιν ἔτι, οὐδὲ διψήσουσιν ἔτι, οὐδὲ μὴ πέσῃ ἐπ᾽ αὐτοὺς ὁ ἥλιος, οὐδὲ πᾶν καῦμα· [8] Jonah 4:8a: “And it came to pass, when the sun did arise, that God prepared a vehement east wind (ר֤וּחַ קָדִים֙ חֲרִישִׁ֔ית; πνεύματι καύσωνος συγκαίοντι, a wind of burning heat blazing, in the Septuagint); and the sun beat upon the head of Jonah, that he fainted…” [9] Isaiah 49:10a: “They shall not hunger nor thirst; neither shall the heat (שָׁרָב; καύσων, in the Septuagint) nor sun smite them…” [10] Ezekiel 17:10a: “Yea, behold, being planted, shall it prosper? shall it not utterly wither, when the east wind (ר֤וּחַ הַקָּדִים֙; ἄνεμον τὸν καύσωνα, in the Septuagint) toucheth it?...” [11] Ezekiel 19:12a: “But she was plucked up in fury, she was cast down to the ground, and the east wind (וְר֥וּחַ הַקָּדִ֖ים; ἄνεμος ὁ καύσων, in the Septuagint) dried up her fruit…” [12] Hosea 12:1a: “Ephraim feedeth on wind, and followeth after the east wind (קָדִים; καύσωνα, in the Septuagint)…” [13] Hosea 13:15a: “Though he be fruitful among his brethren, an east wind (קָדִים֩ ר֙וּחַ; ἄνεμον καύσωνα, in the Septuagint) shall come, the wind of the Lord shall come up from the wilderness, and his spring shall become dry, and his fountain shall be dried up…” [14] Genesis 31:40: “Thus I was; in the day the drought consumed me (אֲכָלַ֥נִי חֹ֖רֶב; συγκαιόμενος τῷ καύματι, I was set ablaze with burning, in the Septuagint), and the frost by night; and my sleep departed from mine eyes.” [15] Matthew 20:12: “Saying, These last have wrought but one hour, and thou hast made them equal unto us, which have borne the burden and heat (τὸν καύσωνα) of the day.” [16] Matthew 13:6: “And when the sun was up, they were scorched (ἐκαυματίσθη); and because they had no root, they withered away.” [17] 1 Peter 4:12: “Beloved, think it not strange concerning the burning (πυρώσει) which is to try you, as though some strange thing happened unto you.”