Poole on Revelation 3:4: Worthy of White
Verse 4: Thou hast (Acts 1:15) a few names even in Sardis which have not (Jude 23) defiled their garments; and they shall walk with me (Rev. 4:4; 6:11; 7:9, 13) in white: for they are worthy.
[But thou hast (He mitigates the reprimand [Gomar, thus Ribera], with a qualification and promise [Gomar]; that is to say, Although many perish by thy negligence, yet not all [Ribera]) a few names] That is, a few men (Estius), a few Christians (Menochius, Lapide). He uses names in the place of heads or persons (Gomar, Beza, Grotius, thus Castalio, Drusius, Ribera, Lapide, Menochius), as in Acts 1:15 and Revelation 11:13 (Grotius, Ribera). Thus also Seneca’s Concerning the Reception of Benefits 5:22. Tibullus, The name of woman is not faithful. Horace, O father, the name of daughter has been left behind (Lapide). Thus He speaks, either, 1. because men are wont to be called by their own names (Estius): a Metaphor from civil and military use, in accordance with the enrollment of the names of subordinates (Gomar). Or, 2. to indicate their excellence, for by their integrity they had acquired for themselves a name in Christ (Durham). Names in the place of men named, who on account of their extraordinary virtues and illustrious deeds were great of name and reputation in the Church (Pererius out of Ambrose). Or, 3. because He speaks of good and elect men, whom God knows by name, John 10:3 (Estius). Thus Exodus 33:12 (Pererius), and their names were written in heaven (certain interpreters in Ribera). Or, 4. from a Hebraism: abstractions in the place of concretes, name in the place of the thing named, or him whose name it is (Ribera). He stirs the Bishop by examples brought forth from the people (Grotius).
[Which have not defiled, etc.] He notes their innocence (Gomar, thus Menochius), either simply; or, inasmuch as, as from evil, so also from the external appearance of evil (which is shadowed forth by garments), they abstained (Gomar). They are not harlots, like the Nicolaitans (Piscator), who defiled themselves and their garments with wantonness (Gomar). The garment of the soul is the conscience: this is polluted by sins, a pure conscience is preserved by innocence and sanctity: whatever is opposed to holiness is μολυσμὸς, 2 Corinthians 7:1; μιάσματα, 2 Peter 2:20; σπῖλος, James 1:27 (Grotius). As Christ is the garment which we put on by faith and baptism, so also holiness was granted by regeneration after the likeness of a clean and bright garment, which covers our nakedness and adorns us. And in the early Church, to indicate this, the old garments were put off before Baptism, and new garments were put on at Baptism (Gomar).
Thou hast a few names even in Sardis, a few persons even in that polluted place, which have not defiled their garments; who have kept their integrity and innocency. There is a garment of Christ’s righteousness, which, once put on, is never lost, nor can be defiled; but there are garments of holiness also: hence the apostle calls to Christians to be clothed with humility. As sin is expressed under the notion of nakedness, so holiness is expressed under the notion of a garment, Ezekiel 16:10; 1 Peter 5:5. Those who have not defiled their garments, are those that have kept a pure conscience.
[And they shall walk with me (that is, they shall delight in my presence and fellowship [Durham]: The with me indicates sharing and similitude of glory [Cluverus]) in white (understand, garments [Drusius, Piscator, etc.]: An Hebraic ellipsis), ἐν λευκοῖς] Whites (Beza, Piscator). Λευκὰ ἱμάτια, white garments, here and in Revelation 3:18; 4:4; they are shining garments, as we learn in Matthew 17:2; Luke 9:29; John 20:12. Thus also στολαὶ λευκαὶ, white robes, in Revelation 6:11; 7:9, 13. Whom the King holds in the highest honor, those and their companions he wills to be and be clothed magnificently. Such were these to Christ in this very life (Grotius). The sense: They will be in perpetual delights. For a bright garment is an indicator of joy, Ecclesiastes 9:8 (Ribera) [on which place see the Synopsis]. In the most pure and splendid blessedness (Lapide); they will be clothed with the robe of immortality, brightness (Lapide, Menochius), and glory (Lapide, Menochius, Durham, Gomar, Pareus), both with respect to their souls, and also with respect to their bodies, Matthew 13:43; 1 Corinthians 15; Philippians 3:21 (Durham), of which glory white garments are established as a sign, Matthew 17:2; Acts 1:10; Revelation 4:4 (Gomar). He promises a Kingdom and triumph to these (Pareus). This is a symbol of dignity Royal, but heavenly (Piscator). Among the Romans and other nations with candidâ, a white, or linen garment were clothed (Cluverus) the nobles (Drusius), and those striving after honors (Cluverus); thence they were called candidates (Drusius), also Kings, and Conquerors (Cluverus, Pareus, Gomar). Priests also among the Jews were ministering dressed in white (Dieu). The sense, therefore, is, Like Kings and Priests, like conquerors of the world and of Demons, they shall be crowned with emblems of perpetual honor and joy (Cluverus): clothed in a triumphal garment, they shall reign in the heavens (Gomar).
[For they are worthy] That is, fit (Beza), or suitable, like fruits worthy of repentance, Matthew 3:8 (Durham). That language of worthy signifies a certain congruence between the acts and the honor rendered for the acts, even if the honor surpasses the act, as in Luke 7:4 (Grotius); that is to say, they separated themselves and kept themselves pure, while others were polluted (Durham): therefore, it is suitable and appropriate that I confirm them as my own (Cocceius, similarly Durham), and dress them in white, inasmuch as others are polluted (Durham). Worthy, not of themselves, or by any merit (Gomar, Cluverus), or on account of righteousness (Cluverus) (to which Romans 8:8 is opposed [Gomar]); but by the grace of God (Piscator), and the gratuitous promise (Gomar), and acceptance in Christ (Beza). Or, worthy, comparatively with the impious (Cameron). He implied that the Angel of Sardis was otherwise unworthy (Cocceius).
And they shall walk with me in white: the Romans used to clothe their nobles, and such as were competitors for honours, in white garments; the priests and Levites also amongst the Jews, when they ministered, were clothed in white, 2 Chronicles 5:12. God and his holy angels are in Scripture set out to us as clothed in white, Daniel 7:9; Matthew 17:2; 28:3. Those that triumphed upon victories obtained, were clothed in white amongst the Romans. To these usages, or some of them, the allusion is, and the meaning is, they shall be to me as kings, and priests, and nobles, they shall be made partakers of my glory: for they are worthy; though they have not merited it, yet I have judged them worthy; they are worthy, though not with respect to their merit, yet with respect to my promise.
 Greek: ἀλλ᾽ ὀλίγα ἔχεις ὀνόματα ἐν Σάρδεσιν, ἃ οὐκ ἐμόλυναν τὰ ἱμάτια αὐτῶν· καὶ περιπατήσουσιν μετ᾽ ἐμοῦ ἐν λευκοῖς, ὅτι ἄξιοί εἰσιν.  Revelation 11:13b: “…and in the earthquake were slain the names (ὀνόματα) of men seven thousand…”  Lucius Annæus Seneca (c. 4 BC-65 AD) was a Roman philosopher and dramatist.  De Beneficiis.  Albius Tibullus (c. 54-19 BC) was a writer of Latin poems and elegies. Two volumes of his poetry survive.  Luke 10:20.  Revelation 3:4a: “Thou hast a few names even in Sardis which have not defiled (ἐμόλυναν) their garments…”  2 Corinthians 7:1: “Having therefore these promises, dearly beloved, let us cleanse ourselves from all filthiness (μολυσμοῦ) of the flesh and spirit, perfecting holiness in the fear of God.”  2 Peter 2:20a: “For if after they have escaped the pollutions (τὰ μιάσματα) of the world through the knowledge of the Lord and Saviour Jesus Christ…”  James 1:27: “Pure religion and undefiled before God and the Father is this, To visit the fatherless and widows in their affliction, and to keep himself unspotted (ἄσπιλον) from the world.”  John Cameron (1580-1625) was a Protestant divine of great distinction, serving as Professor Philosophy at Sedan, Professor of Divinity at Saumur (1608) and at Glasgow (1620). He is the father of the Amyraldian doctrine. He wrote, among other things, Prælectiones in Selectiora Quædam Loca Novi Testamenti and Myrothecium Evangelicum, in quo Aliquot Loca Novi Testamenti Explicantur.  The abbreviation here Co. appears to be incomplete. It could refer to either Cotterius or Cocceius.