I must needs glory ( καυχασθα δε ). This is the reading of B L Latin Syriac, but Aleph D Bohairic have  δε while K M read  δη. The first is probably correct. He must go on with the glorying already begun, foolish as it is, though it is not expedient ( ου συμφερον ).

Visions ( οπτασιας ). Late word from  οπταζω. See on Lu 1:22; Ac 26:19.

Revelations of the Lord ( αποκαλυψεις Κυριου ). Unveilings (from  αποκαλυπτω as in Re 1:1). See on 2Th 1:7; 1Co 1:7; 14:26. Paul had both repeated visions of Christ (Ac 9:3; 16:9; 18:9; 22:17; 27:23f.) and revelations. He claimed to speak by direct revelation (1Co 11:23; 15:3; Ga 1:12; Eph 3:3, etc.).

I know a man ( οιδα ανθρωπον ). Paul singles out one incident of ecstasy in his own experience that he declines to describe. He alludes to it in this indirect way as if it were some other personality.

Fourteen years ago ( προ ετων δεκατεσσαρων ). Idiomatic way of putting it, the preposition  προ (before) before the date (Robertson, Grammar, p. 621f.) as in Joh 12:1. The date was probably while Paul was at Tarsus (Ac 9:30; 11:25). We have no details of that period. Caught up ( Î±ÏÏ€Î±Î³ÎµÎ½Ï„α ). Second aorist passive participle of  Î±ÏÏ€Î±Î¶Ï‰, to seize (see on Mt 11:12). Even to the third heaven ( ÎµÏ‰Ï‚ τριτου ουρανου ). It is unlikely that Paul alludes to the idea of seven heavens held by some Jews (Test. of the Twelve Pat._, Levi ii. iii.). He seems to mean the highest heaven where God is (Plummer).

I do not know ( ουκ οιδα ). Paul declines to pass on his precise condition in this trance. We had best leave it as he has told it.

Into Paradise ( εις παραδεισον ). See on Lu 23:43 for this interesting word. Paul apparently uses paradise as the equivalent of the third heaven in verse 2. Some Jews (Book of the Secrets of Enoch, chapter viii) make Paradise in the third heaven. The rabbis had various ideas (two heavens, three, seven). We need not commit Paul to any "celestial gradation" (Vincent).

Unspeakable words ( αρρητα ρηματα ). Old verbal adjective ( α privative,  ρητος from  ρεω ), only here in N.T.

Not lawful ( ουκ εξον ). Copula  εστιν omitted. Hence Paul does

not give these words.

But on mine own behalf ( υπερ δε εμαυτου ). As if there were two Pauls. In a sense there were. He will only glory in the things mentioned above, the things of his weaknesses (11:30).

I shall not be foolish ( ουκ εσομα αφρων ). Apparent contradiction to 11:1,16. But he is here speaking of the Paul "caught up" in case he should tell the things heard (condition of the third class,  εαν and first aorist subjunctive  θελησω ).

Of me ( εις εμε ). To my credit, almost like dative (cf.  εν εμο in 1Co 14:11).

By reason of the exceeding greatness ( τη υπερβολη ). Instrumental case, "by the excess."

That I should not be exalted overmuch ( ινα μη υπεραιρωμα ). Present passive subjunctive in final clause of  υπεραιρω, old verb to lift up beyond, only here in N.T. This clause is repeated at the end of the sentence.

A thorn in the flesh ( σκολοπς τη σαρκ ). This old word is used for splinter, stake, thorn. In the papyri and inscriptions examples occur both for splinter and thorn as the meaning. In the LXX it is usually thorn. The case of  τη σαρκ can be either locative (in) or dative (for). What was it? Certainly it was some physical malady that persisted. All sorts of theories are held (malaria, eye-trouble, epilepsy, insomnia, migraine or sick-headache, etc.). It is a blessing to the rest of us that we do not know the particular affliction that so beset Paul. Each of us has some such splinter or thorn in the flesh, perhaps several at once.

Messenger of Satan ( αγγελος Σατανα ). Angel of Satan, the affliction personified.

Buffet ( κολαφιζη ). See on Mt 26:67; 1Co 4:11 for this late and rare word from  κολαφος, fist. The messenger of Satan kept slapping Paul in the face and Paul now sees that it was God's will for it to be so.

Concerning this thing ( υπερ τουτου ). More likely, "concerning this messenger of Satan."

That it might depart from me ( ινα αποστη αφ' εμου ). Second aorist active (intransitive) subjunctive of  αφιστημ in final clause, "that he stand off from me for good."

He hath said ( ειρηκεν ). Perfect active indicative, as if a final word. Paul probably still has the thorn in his flesh and needs this word of Christ.

Is sufficient ( αρκε ). Old word of rich meaning, perhaps kin to Latin arceo, to ward off against danger. Christ's grace suffices and abides.

Is perfected ( τελειτα ). Present passive indicative of  τελεω, to finish. It is linear in idea. Power is continually increased as the weakness grows. See Php 4:13 for this same noble conception. The human weakness opens the way for more of Christ's power and grace.

Most gladly rather ( ηδιστα μαλλον ). Two adverbs, one superlative ( ηδιστα ), one comparative ( μαλλον ). "Rather" than ask any more (thrice already) for the removal of the thorn or splinter "most gladly will I glory in my weaknesses." Slowly Paul had learned this supreme lesson, but it will never leave him (Ro 5:2; 2Ti 4:6-8).

May rest upon me ( επισκηνωση επ' εμε ). Late and rare verb in first aorist active subjunctive with  ινα (final clause), to fix a tent upon, here upon Paul himself by a bold metaphor, as if the Shechinah of the Lord was overshadowing him (cf. Lu 9:34), the power ( δυναμις ) of the Lord Jesus.

Wherefore I take pleasure ( διο ευδοκω ). For this noble word see on Mt 3:17; 2Co 5:8. The enemies of Paul will have a hard time now in making Paul unhappy by persecutions even unto death (Php 1:20-26). He is not courting martyrdom, but he does not fear it or anything that is "for Christ's sake" ( υπερ Χριστου ).

For when ( οταν γαρ ). "For whenever," indefinite time.

Then I am strong ( τοτε δυνατος ειμ ). At that very time, but not in myself, but in the fresh access of power from Christ for the emergency.

I am become foolish ( γεγονα αφρων ). Perfect active indicative of  γινομα. In spite of what he said in verse 6 that he would not be foolish if he gloried in the other Paul. But he feels that he has dropped back to the mood of 11:1,16. He has been swept on by the memory of the ecstasy.

For I ought to have been commended by you ( εγω γαρ ωφειλον υφ' υμων συνιστασθα ). Explanation of "ye compelled me." Imperfect active  ωφειλον of  οφειλω, to be under obligation, and the tense here expresses an unfulfilled obligation about the present. But  συνιστασθα is present passive infinitive, not aorist or perfect passive. He literally means, "I ought now to be commended by you" instead of having to glorify myself. He repeats his boast already made (11:5f.), that he is no whit behind "the super-extra apostles" (the Judaizers), "though I am nothing" ( ε κα ουδεν ειμ ). Even boasting himself against those false apostles causes a reaction of feeling that he has to express (cf. 1Co 15:9; 1Ti 1:15f.).

Of an apostle ( του αποστολου ). "Of the apostle" (definite article). Note the three words here for miracles wrought by Paul ( σημεια, signs,  τερατα, wonders,  δυναμεις, powers or miracles) as in Heb 2:4.

Wherein ye were made inferior ( ο ησσωθητε ). First aorist passive indicative of  ησσοομα, the text of Aleph B D instead of the usual  ηττηθητε from the common  ητταομα to be inferior or less from the comparative  ηττων. See  ησσων in verse 15.  Hο is the neuter accusative with the passive verb (Robertson, Grammar, p. 479).

Forgive me this wrong ( χαρισασθε μο την αδικιαν ταυτην ). Consummate irony to the stingy element in this church (cf. 11:9).

Third time I am ready to come ( τριτον τουτο ετοιμως εχω ). Had he been already twice or only once? He had changed his plans once when he did not go (1:15f.). He will not change his plans now. This looks as if he had only been once (that in Ac 18). Note the third use of  καταναρκαω (11:9; 12:13,14). They need not be apprehensive. He will be as financially independent of them as before. "I shall not sponge on you."

Not yours, but you ( ου τα υμων, αλλα υμας ). The motto of every real preacher.

To lay up ( θησαυριζειν ). For this use of the verb see 1Co 16:2 (Mt 6:19-21; Jas 5:3).

I will most gladly spend and be spent ( ηδιστα δαπανησω κα εκδαπανηθησομα ). Both future active of old verb  δαπαναω (Mr 5:26) to spend money, time, energy, strength and the future passive of  εκδαπαναω, late compound to spend utterly, to spend out, ( εκ- ), to spend wholly. Only here in N.T.

I did not myself burden you ( εγω ου κατεβαρησα υμας ). First aorist active of late verb  καταβαρεω, to press a burden down on one. Only here in N.T.

Crafty ( πανουργος ). Old word from  παν, all, and  εργο, to do anything (good or bad). Good sense is skilful, bad sense cunning. Only here in N.T. and Paul is quoting the word from his enemies.

With guile ( δολω ). Instrumental case of  δολος, bait to catch fish with. The enemies of Paul said that he was raising this big collection for himself. Moffatt has done well to put these charges in quotation marks to make it plain to readers that Paul is ironical.

Did I take advantage ( επλεονεκτησα ). Paul goes right to the point without hedging. For this verb from  πλεον and  εχω, to have more, see on 2Co 2:11; 7:2.

By any one of them ( τινα--δι' αυτου ). An anacoluthon for  τινα is left in the accusative without a verb and  δι' αυτου takes up the idea, "as to any one by him."

Whom ( ων ). The genitive relative is attracted from the accusative  ους into the case of the unexpressed antecedent  τουτον ).  Μη expects the negative answer as does  μητ in 18.

The brother ( τον αδελφον ). Probably the brother of Titus (cf. 8:18).

Did Titus take advantage of you? ( μητ επλεονεκτησεν υμας Τιτοσ? ). That puts the issue squarely.

By the same Spirit ( τω αυτω πνευματ ). That translation refers to the Holy Spirit and makes the case instrumental. The locative case, "in the same spirit," makes it mean that Paul's attitude is the same as that of Titus and most likely is correct, for "in the same steps" ( τοις αυτοις ιχνεσιν ) is in locative case.

Ye think all this time ( παλα δοκειτε ). Progressive present indicative, "for a long time ye have been thinking."

We are excusing ourselves ( απολογουμεθα ). He is not just apologizing, but is in deadly earnest, as they will find out when he comes.

Lest by any means, when I come, I should find you not such as I would ( μη πως ελθων ουχ οιους θελω ευρω υμας ). An idiomatic construction after the verb of fearing ( φοβουμα ) with  μη πως as the conjunction and with  ουχ as the negative of the verb  ευρω (second aorist active subjunctive of  ευρισκω ),  μη the conjunction,  ουχ the negative. See Robertson, Grammar, p. 995.

And I be found ( καγω ευρεθω ). Same construction with first aorist passive subjunctive.

Such as ye would not ( οιον ου θελετε ). Neat change in voice just before and position of the negative here.

Lest by any means ( μη πως ). Still further negative purpose by repeating the conjunction. With graphic pen pictures Paul describes what had been going on against him during his long absence.

Backbitings ( καταλαλια ). Late and rare word. In N.T. only here and 1Pe 2:1. If it only existed nowhere else!

Whisperings ( ψιθυρισμο ). Late word from  ψιθυριζω, to whisper into one's ear. An onomatopoetic word for the sibilant murmur of a snake charmer (Ec 10:11). Only here in N.T.

Swellings ( φυσιωσεις ). From  φυσιοω, to swell up, late word only here and in ecclesiastical writers. Did Paul make up the word for the occasion? See on 1Co 4:6 for verb.

Tumults ( ακαταστασια ). See on 2Co 6:5.

When I come again ( παλιν ελθοντος μου ). Genitive absolute. Paul assumes it as true.

Lest my God humble me ( μη ταπεινωση με ο θεος μου ). Negative final clause ( μη and first aorist active subjunctive), going back to  φοβουμα in 20. He means a public humiliation as his fear. The conduct of the church had been a real humiliation whether he refers to a previous visit or not.

That have sinned heretofore ( των προημαρτηκοτων ). Genitive plural of the articular perfect active participle of  προαμαρτανω to emphasize continuance of their sinful state as opposed to  μη μετανοησαντων (did not repent) in the aorist tense.