Verse 18: I counsel thee (Is. 55:1; Matt. 13:44; 25:9) to buy of me gold tried in the fire, that thou mayest be rich; and (2 Cor. 5:3; Rev. 7:13; 16:15; 19:8) white raiment, that thou mayest be clothed, and that the shame of thy nakedness do not appear; and anoint thine eyes with eyesalve, that thou mayest see.
[I advise, etc., συμβουλεύω σοι ἀγοράσαι—χρυσίον πεπυρωμένον ἐκ πυρός, etc.] I counsel thee (I who am the most wise Counselor, Isaiah 9:6 [Durham]: He was able to command, but He prefers to take up the character of one persuading [Grotius, similarly Durham], partly, so that He might elicit willing consent from them; partly, so that He might show His friendly affection [Durham]; [partly] because that which He is about to say to the Bishop, and to those like him, is most useful [Grotius]) that thou buy (that is, that thou acquire or secure [Grotius, Piscator, Estius], even with some labor, as in Proverbs 3:14; 23:23 [Grotius], and at the cost of pleasures [Ribera, Menochius], by the subjugation of the flesh [Grotius], and with constant prayers [Grotius, similarly Piscator, Pareus]; and that thou receive the thing freely bestowed [Piscator, similarly Estius, Durham, Pareus], as it is evident from a comparison with Isaiah 55:1-3 [Durham, similarly Pareus, Estius]: Therefore, there is a Catachresis in the language of buying [Estius, thus Piscator]: For charity is acquired with no price or merit, but is obtained freely, especially as far as its beginning [Estius]: Compare Matthew 13:44, 45 [Grotius] and John 7:37 [Piscator]: And what price, I ask, to Christ [who is the thing to be bought, Isaiah 55:3], could be fixed, or paid [Durham], especially by a beggar [Pareus, similarly Durham]? The language of buying indicates mutual consent, or agreement, between God and men [Durham]) from me gold (that is, either, 1. ardent love [Menochius, similarly Estius, Ribera, Tirinus out of Rich. and Alcasar, etc.], or enduring passion, with which God and the neighbor are loved [Grotius]; or, 2. faith [Pareus, Cluverus, Gomar], founded upon the word of God, which is purer and more precious than gold [Cluverus]; or, 3. wisdom and piety obtained from the word of God [Piscator]) by fire (or, out of fire [Montanus, Valla, Erasmus, Vatablus]: I prefer by fire; for ἐκ, out of, like מִן in Hebrew, often is a mark of Instrument [Grotius]) tried (or, proved [Vulgate], that is, most pure [Ribera]: Πυροῦν is to prove, to boil: That gold is best which is thoroughly purged by fire: See Revelation 1:15 [Grotius]) that thou mayest be rich. Before God (Pareus). That thou mightest receive greater gifts daily, not in mere opinion, but in fact, 1 Corinthians 4:8; 2 Corinthians 8:9; 1 Timothy 6:17; Titus 3:6 (Grotius).
[And, etc., καὶ—ἵνα περιβάλῃ, etc.] And white garments (that is, splendid [Ribera, Grotius], for the color white has more splendor and light than other colors [Ribera]: He understands innocence and purity, or holiness, of life [Menochius, similarly Ribera, Gomar, Piscator]; or, works of virtue [Menochius, similarly Grotius], proceeding from love [Grotius]), that thou mayest be clothed (or, with which thou mayest be dressed [Grotius]), that may not appear the shame (or, indecency, or, disgrace [Erasmus]) of thy nakedness (Piscator), or, thy ignominious, or shameful, nakedness (Vatablus, Beza), or, thy shame naked, and exposed to the eyes of all (Vatablus). עֶרְוָה is sometimes translated αἰσχύνη/shame, other times γύμνωσις/nakedness. Therefore, this saying is like earth of clay, the same thing twice. Now, shameful things through a figurative expression signify sins. In a man emended, these things no longer appear: God remembers them not (Grotius).
[And eyesalve, etc., καὶ κολλούριον, etc.] Thus also writes Anatolius. Some write, κολούριον παρὰ τὸ κολούειν τὸ ῥεῖν, κολούριον/colourion/ eye-salve, because τὸ κολούειν, it stops, the flux: Others, κολλούριον, because it is made after the form of a certain loaf. You have some descriptions collyriorum, of eyesalves, against diseases of the eye in Celsus’ The True Word 6, where also he uses inungere, to anoint, as ἐγχρίειν, to anoint, is used here. Some manuscripts have here ἐγχρῖσαι τοὺς ὀφθαλμούς, to anoint the eyes; that is, obtain from God a clear view of God and of future events (Grotius). [Thus they translate:] And that with eyesalve thou anoint thine eyes, so that thou mayest see (Beza, Piscator). That is, what things are useful for thy salvation (Zegers); or, so that thou mayest understand heavenly doctrine (Piscator); or, so that thou mayest see how great are the future joys of good men, and the sufferings of evil men (Ribera); or, so that thou mayest recognize the wretched state of thy soul (Menochius). Collyrium is a type of drug or medicine (Erasmus, Piscator), for the eyes (Piscator, thus Zegers, Camerarius, Menochius), particularly (Menochius) against inflammation of the eyes (Gagnæus, Menochius). He understands in this place, either, 1. tribulations, out of a comparison with the following verse, which have great force for purging the minds of men from vices and errors with which they are defiled in prosperity (Estius); or, 2. his dejection and humiliation, and a recognition of his frailty (Gagnæus); or, humility, which opens our eyes so that we might recognize our wretchedness (Menochius); or, 3. heavenly doctrine (Piscator); or, 4. heavenly wisdom, gathered out of a consideration of the attributes of God, the passion of Christ, and the futures of good and evil men (Tirinus out of Primasius and Anselm and Rich. etc.). Cast down the excessive love of thyself and of earthly things, which completely blind thee, so that thou mayest see, etc. (Ribera). Others: All these things, gold, white garments, and eyesalve, designate Christ Himself with all His benefits; for He alone is able to produce these conditions, and to effect this alteration in spiritual state (Durham).
To buy of me, etc.:Buying being the usual way amongst men to procure what they want, it is not to be wondered at, that the procuring of that spiritual blessing here mentioned is expressed under this notion; though our buying of God spiritual good things be (as the prophet expresseth it, Isaiah 55:1) without money and without price. It is not to be doubted, but that which is here propounded to be bought (that is, obtained, and procured by such ways and means as God hath directed) is Christ himself, with all his benefits, in whom there is a sufficient spiritual supply for all our spiritual wants; that which to the soul will answer whatever gold serveth the body for; and which to the soul answereth what clothing is to the body, namely, righteousness, wherein a soul may stand before God; and that which will answer what salves are to the body for the cure of its wounds, namely, consolation, and healing of all spiritual wounds and infirmities; in short, whatever thou hast need of, considered either as poor, wretched, and miserable, or as blind and naked.
 Greek: συμβουλεύω σοι ἀγοράσαι παρ᾽ ἐμοῦ χρυσίον πεπυρωμένον ἐκ πυρός, ἵνα πλουτήσῃς, καὶ ἱμάτια λευκά, ἵνα περιβάλῃ, καὶ μὴ φανερωθῇ ἡ αἰσχύνη τῆς γυμνότητός σου· καὶ κολλούριον ἔγχρισον τοὺς ὀφθαλμούς σου, ἵνα βλέπῃς.  A Catachresis is an improper use of a word.  See Psalm 19:10.  Revelation 1:15: “And his feet like unto fine brass, as if they burned in a furnace (ὡς ἐν καμίνῳ πεπυρωμένοι); and his voice as the sound of many waters.”  Greek: ἡ αἰσχύνη τῆς γυμνότητός.  For example, Exodus 28:42a: “And thou shalt make them linen breeches to cover their nakedness (עֶרְוָה; ἀσχημοσύνην, in the Septuagint)…”  For example, Genesis 9:22: “And Ham, the father of Canaan, saw the nakedness (עֶרְוַת; γύμνωσιν, in the Septuagint) of his father, and told his two brethren without.”  This Anatolius is likely Anatolius of Laodicea (d. 283), for he was not only Bishop of Laodicea, but also a natural philosopher, knowledgeable in the field of medicine.  Some Byzantine manuscripts and Codex Sinaiticus read κολλύριον/eyesalve; other Byzantine manuscripts and Codex Alexandrinus, κολλούριον/eyesalve, related to κολλούρα, a loaf of bread; still other Byzantine manuscripts read κουλούριον/ eyesalve, perhaps derived from the verbal root κολούω, to cut short.  Revelation 3:18: “I counsel thee to buy (ἀγοράσαι, in the infinitive) of me gold tried in the fire, that thou mayest be rich; and white raiment, that thou mayest be clothed, and that the shame of thy nakedness do not appear; and anoint (ἔγχρισον, imperative in the Textus Receptus) thine eyes with eyesalve, that thou mayest see.” Codices Sinaiticus, Alexandrinus, and Ephræmi Rescriptus read it in the infinite, ἐγχρῖσαι, to anoint, in conformity with ἀγοράσαι, to buy. Many manuscripts in the Byzantine tradition read it in the singular imperative, ἔγχρισον, anoint.