Verse 19: (Job 5:17; Prov. 3:11, 12; Heb. 12:5, 6; Jam. 1:12) As many as I love, I rebuke and chasten: be zealous therefore, and repent.
[Whom I love (as friends, sons, and my future heirs [Tirinus]: Whom I have resolved not to cast away completely on account of abiding sins, but to endure: For here φιλῶ, I love, is used, not absolutely, but comparatively, as μισεῖν, to hate, elsewhere: See 2 Corinthians 2:4; Galatians 6:11 [Grotius]: understand, those [Camerarius]) I charge and chasten] I reprehend with words; I chasten with lashes (Grotius, similarly Cluverus, Durham, Ribera). Thus you have the verb ἐλέγχειν in John 8:46 and 1 Timothy 5:20. But, παιδεύειν in 1 Corinthians 11:32; 1 Timothy 1:20; Hebrews 12:7 (Grotius). The words are taken out of Proverbs 3:12 (Grotius, thus Drusius). Lest He should increase their wretchedness with desperation, He raises them unto the hope of salvation, and teaches that this sharp rebuke is a proof of His love (Cotterius): that is to say, Receive these admonitions as proofs of a loving heart, as they actually are (Menochius, similarly Cluverus, Gomar, Durham, Pareus). Others: The sense: These persecutions and calamities (which cause thee to doubt of the promises of Christ, and render thee torpid) are pledges of my love, by which I exercise the elect, so that they, purer and better, might pass through (Ribera).
I rebuke and chasten; ἐλέγχω καὶ παιδεύω: the words may be translated, I convince and instruct, or deal with them as children; but it also signifies to chasten, and is so translated, 1 Corinthians 11:32; Hebrews 12:7; we translate it learn, 1 Timothy 1:20. By these words Christ lets this angel know, that although he had in this epistle dealt smartly with him, yet he had done it from a principle of love, as a father to a child, Hebrews 12:7.
[Be zealous, etc., ζήλωσον, etc.] Understand, ἐμέ, for me (Beza). This verb sometimes has an Accusative of the thing for which we are zealous, as in 1 Corinthians 12:31; 14:1; Galatians 4:17; it is sometimes set down intransitively, as here, and in Numbers 11:29; 1 Kings 19:14; 1 Corinthians 13:4 (Ribera). [Thus they translate it:] Be fervent (or, grow hot [Grotius], understand, with zeal for me [Beza]; or, be zealous [Vulgate], love ardently [Piscator, thus Menochius], be inflamed with zeal [Tirinus, thus Ribera] against all lukewarmness and torpor, whether thine own, or of those belonging to thee, chasing those things far off [Tirinus]; zeal for thy salvation [Menochius, thus Ribera], and that of others, take up [Menochius]: Ardent love is called ζῆλος/ zeal, קִנְאָה, in Numbers 11:29; Psalm 69:9; and elsewhere: Some manuscripts read ζήλευε [Grotius]: By this verb He prescribes a laudable ambition for piety and virtue, and ardent affection in the observance of religion [Camerarius]) therefore (O thou lukewarm [Grotius]), and repent (Piscator, etc.). From thy former lukewarmness and hypocrisy (Cluverus), so that thou mightest avoid threatening evils (Ribera). From love for me reform thy life. You see here the reciprocal actions of Christ and Men concerning conversion (Grotius).
Be zealous therefore, and repent; he adviseth him therefore to quit himself of his lukewarmness, and to recover a warmth and zeal for God, repenting of his former coldness and negligence in his duty.
 Greek: ἐγὼ ὅσους ἐὰν φιλῶ, ἐλέγχω καὶ παιδεύω· ζήλωσον οὖν καὶ μετανόησον.  Revelation 3:19: “As many as I love, I rebuke (ἐλέγχω) and chasten (παιδεύω): be zealous therefore, and repent.”  John 8:46a: “Which of you convinceth (ἐλέγχει) me of sin?…”  1 Timothy 5:20: “Them that sin rebuke (ἔλεγχε) before all, that others also may fear.”  1 Corinthians 11:32: “But when we are judged, we are chastened (παιδευόμεθα) of the Lord, that we should not be condemned with the world.”  1 Timothy 1:20: “Of whom is Hymenaeus and Alexander; whom I have delivered unto Satan, that they may learn (παιδευθῶσι) not to blaspheme.”  Hebrews 12:7: “If ye endure chastening (παιδείαν), God dealeth with you as with sons; for what son is he whom the father chasteneth (παιδεύει) not?”  Proverbs 3:11, 12: “My son, despise not the chastening (παιδείας, in the Septuagint) of the Lord; neither be weary of his correction (ἐλεγχόμενος, when rebuked, in the Septuagint): For whom the Lord loveth he correcteth (παιδεύει/chasteneth, in the Septuagint); even as a father the son in whom he delighteth.”  1 Corinthians 12:31a: “But covet earnestly the best gifts (ζηλοῦτε δὲ τὰ χαρίσματα τὰ κρείττονα)…”  1 Corinthians 14:1: “Follow after charity, and desire spiritual gifts (ζηλοῦτε δὲ τὰ πνευματικά), but rather that ye may prophesy.”  Galatians 4:17: “They are zealous for you (ζηλοῦσιν ὑμᾶς), but not well; yea, they would exclude you, that ye might be zealous for them (ἵνα αὐτοὺς ζηλοῦτε).”  Numbers 11:29a: “And Moses said unto him, Enviest thou for my sakeהַֽמְקַנֵּ֥א אַתָּ֖ה) לִ֑י, with the ל serving as the indirect object marker; ζηλοῖς σύ μοι, in the Septuagint)?…  1 Kings 19:14a: “And he said, I have been very jealous for the Lordקַנֹּ֙א קִנֵּ֜אתִי) לַיהוָ֣ה׀, with the ל serving as the indirect object marker; ζηλῶν ἐζήλωκα τῷ κυρίῳ, in the Septuagint) God of hosts…”  1 Corinthians 13:4a: “Charity suffereth long, and is kind; charity envieth (ζηλοῖ) not…”  Psalm 69:9a: “For the zeal (קִנְאַת) of thine house hath eaten me up…”  Codices Alexandrinus and Ephræmi Rescriptus, and some Byzantine manuscripts, read ζήλευε, the singular, present, imperative form of ζηλεύω. The Textus Receptus and other Byzantine manuscripts read ζήλωσον, the singular, aorist, imperative form of ζηλόω. The meaning is not much affected.