He (εκεινος). "That one" (John of John 5:33). Common demonstrative (that one) in John to point out the subject. Used in John 1:8 of the Baptist as here. John was now in prison and so Christ uses ην (was). His active ministry is over.

The lamp (ο λυχνος). The lamp in the room (Mark 4:21). Old word for lamp or candle as in Matthew 5:15. Used of Christ (the Lamb) as the Lamp of the New Jerusalem (Revelation 21:23). Λαμπας (Matthew 25:1; Matthew 25:3, etc.) is a torch whose wick is fed with oil. The Baptist was not the Light (το φως, John 1:8), but a lamp shining in the darkness. "When the Light comes, the lamp is no longer needed" (Bernard). "Non Lux iste, sed lucerna." Jesus by his own claim is the Light of the World (John 8:12; John 9:5; John 12:46). And yet all believers are in a sense "the light of the world" (Matthew 5:14) since the world gets the Light of Christ through us.

That burneth (ο καιομενος). See Matthew 5:15 for this verb used with λυχνος (lighting a candle or lamp). The lamp that is lit and is burning (present passive participle of καιω, and so is consumed).

And shineth (κα φαινων). See John 1:4 for this verb used of the Logos shining in the darkness. Cf. 1 John 2:8. John was giving light as he burned for those in darkness like these Jews.

And ye were willing (υμεις δε ηθελησατε). "But ye became willing." Ingressive aorist active indicative of θελω. Reference again to John 1:19. Cf. also for the temporary popularity of the Baptist Mark 1:5; Matthew 3:5; Matthew 11:7; Matthew 21:26. The Jews were attracted to John "like moths to a candle" (Bernard).

To rejoice (αγαλλιαθηνα). First aorist passive infinitive of αγαλλιαομα, late word for αγαλλομα for which see Matthew 5:12. "They were attracted by his brightness, not by his warmth" (Bengel). Even so the brightness of John's shining did not really enlighten their minds. "The interest in the Baptist was a frivolous, superficial, and short-lived excitement" (Vincent). It was only "for an hour" (προς ωραν) when they turned against him.