A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
1 Corinthians 5:1
co1 5:1THE INCESTUOUS PERSON AT CORINTH: THE CORINTHIANS REPROVED FOR CONNIVANCE, AND WARNED TO PURGE OUT THE BAD LEAVEN. QUALIFICATION OF HIS FORMER COMMAND AS TO ASSOCIATION WITH SINNERS OF THE WORLD. (Co1 5:1-13)
commonly--rather, "actually" [ALFORD]. Absolutely [BENGEL]. "It is reported," implies, that the Corinthians, though they "wrote" (Co1 7:1) to Paul on other points, gave him no information on those things which bore against themselves. These latter matters reached the apostle indirectly (Co1 1:11).
so much as named--The oldest manuscripts and authorities omit "named": "Fornication of such a gross kind as (exists) not even among the heathen, so that one (of you) hath (in concubinage) his father's wife," that is, his stepmother, while his father is still alive (Co2 7:12; compare Lev 18:8). She was perhaps a heathen, for which reason he does not direct his rebuke against her (compare Co1 5:12-13). ALFORD thinks "have" means have in marriage: but the connection is called "fornication," and neither Christian nor Gentile law would have sanctioned such a marriage, however Corinth's notorious profligacy might wink at the concubinage.
1 Corinthians 5:2
co1 5:2puffed up--with your own wisdom and knowledge, and the eloquence of your favorite teachers: at a time when ye ought to be "mourning" at the scandal caused to religion by the incest. Paul mourned because they did not mourn (Co2 2:4). We ought to mourn over the transgressions of others, and repent of our own (Co2 12:21) [BENGEL].
that--ye have not felt such mourning as would lead to the result that, &c.
taken away from among you--by excommunication. The incestuous person was hereby brought to bitter repentance, in the interval between the sending of the first and second Epistles (Co2 2:5-10). Excommunication in the Christian Church corresponded to that in the Jewish synagogue, in there being a lighter and heavier form: the latter an utter separation from church fellowship and the Lord's house, the former exclusion from the Lord's Supper only but not from the Church.
1 Corinthians 5:3
co1 5:3as absent--The best manuscripts read, "being absent."
present in spirit-- (Kg2 5:26; Col 2:5).
so done--rather, "perpetrated," as the Greek word here is stronger than that for "done" in Co1 5:2. "So," that is, so scandalously while called a brother.
1 Corinthians 5:4
co1 5:4In the name of our Lord Jesus Christ--By His authority and as representing His person and will (Co2 2:10). Join this with "to deliver such a one unto Satan" (Co1 5:5). The clause, "When ye have been gathered together and my spirit (wherein I am 'present,' though 'absent in body,' Co1 5:3), with the power of our Lord Jesus," stands in a parenthesis between. Paul speaking of himself uses the word "spirit"; of Christ, "power." Christ's power was promised to be present with HIS Church "gathered together in His name" (Mat 18:18-20): and here Paul by inspiration gives a special promise of his apostolic spirit, which in such cases was guided by the Holy Spirit, ratifying their decree passed according to his judgment ("I have judged," Co1 5:3), as though he were present in person (Joh 20:21-23; Co2 13:3-10). This power of infallible judgment was limited to the apostles; for they alone had the power of working miracles as their credentials to attest their infallibility. Their successors, to establish their claim to the latter, must produce the former (Co2 12:2). Even the apostles in ordinary cases, and where not specially and consciously inspired, were fallible (Act 8:13, Act 8:23; Gal 2:11-14).
1 Corinthians 5:5
co1 5:5Besides excommunication (of which the Corinthians themselves had the power), Paul delegates here to the Corinthian Church his own special power as an apostle, of inflicting corporeal disease or death in punishment for sin ("to deliver to Satan such an one," that is, so heinous a sinner). For instances of this power, see Act 5:1-11; Act 13:11; Ti1 1:20. As Satan receives power at times to try the godly, as Job (Job 2:4-7) and Paul (Co2 12:7; compare also as to Peter, Luk 22:31), much more the ungodly. Satan, the "accuser of the brethren" (Rev 12:10) and the "adversary" (Pe1 5:8), demands the sinner for punishment on account of sin (Zac 3:1). When God lets Satan have his way, He is said to "deliver the sinner unto Satan" (compare Psa 109:6). Here it is not finally; but for the affliction of the body with disease, and even death (Co1 11:30, Co1 11:32), so as to destroy fleshly lust. He does not say, "for the destruction of the body," for it shall share in redemption (Rom 8:23); but of the corrupt "flesh" which "cannot inherit the kingdom of God," and the lusts of which had prompted this offender to incest (Rom 7:5; Rom 8:9-10). The "destruction of the flesh" answers to "mortify the deeds of the body" (Rom 8:13), only that the latter is done by one's self, the former is effected by chastisement from God (compare Pe1 4:6):
the spirit . . . saved--the spiritual part of man, in the believer the organ of the Holy Spirit. Temporary affliction often leads to permanent salvation (Psa 83:16).
1 Corinthians 5:6
co1 5:6Your glorying in your own attainments and those of your favorite teachers (Co1 3:21; Co1 4:19; Co1 5:2), while all the while ye connive at such a scandal, is quite unseemly.
a little leaven leaveth . . . whole lump-- (Gal 5:9), namely, with present complicity in the guilt, and the danger of future contagion (Co1 15:33; Ti2 2:17).
1 Corinthians 5:7
co1 5:7old leaven--The remnant of the "old" (Eph 4:22-24) heathenish and natural corruption. The image is taken from the extreme care of the Jews in searching every corner of their houses, and "purging out" every particle of leaven from the time of killing the lamb before the Passover (Deu 16:3-4). So Christians are continually to search and purify their hearts (Psa 139:23-24).
as ye are unleavened--normally, and as far as your Christian calling is concerned: free from the leaven of sin and death (Co1 6:11). Paul often grounds exhortations on the assumption of Christian professors' normal state as realized (Rom 6:3-4) [ALFORD]. Regarding the Corinthian Church as the Passover "unleavened lump" or mass, he entreats them to correspond in fact with this their normal state. "For Christ our Passover (Exo 12:5-11, Exo 12:21-23; Joh 1:29) has been (English Version, "is") sacrificed for us"; that is, as the Jews began the days of unleavened bread with the slaying of the Passover lamb, so, Christ our Passover having been already slain, let there be no leaven of evil in you who are the "unleavened lump." Doubtless he alludes to the Passover which had been two or three weeks before kept by the Jewish Christians (Co1 16:8): the Gentile Christians probably also refraining from leavened bread at the love-feasts. Thus the Jewish Passover naturally gave place to our Christian Easter. The time however, of keeping feast (metaphorical; that is, leading the Christian life of joy in Christ's finished work, compare Pro 15:15) among us Christians, corresponding to the Jewish Passover, is not limited, as the latter, to one season, but is ALL our time; for the transcendent benefits of the once-for-all completed sacrifice of our Passover Lamb extends to all the time of our lives and of this Christian dispensation; in no part of our time is the leaven of evil to be admitted.
For even--an additional reason, besides that in Co1 5:6, and a more cogent one for purging out every leaven of evil; namely, that Christ has been already sacrificed, whereas the old leaven is yet unremoved, which ought to have been long ago purged out.
1 Corinthians 5:8
co1 5:8not . . . old leaven--of our unconverted state as Jews or heathen.
malice--the opposite of "sincerity," which allows no leaven of evil to be mixed up with good (Mat 16:6).
wickedness--the opposite of "truth," which allows not evil to be mistaken for good. The Greek for "malice" means the evil habit of mind; "wickedness," the outcoming of the same in word and deed. The Greek for "sincerity" expresses literally, a thing which, when examined by the sun's light, is found pure and unadulterated.
1 Corinthians 5:9
co1 5:9I wrote . . . in an epistle--rather, "in the Epistle": a former one not now extant. That Paul does not refer to the present letter is proved by the fact that no direction "not to company with fornicators" occurs in the previous part of it; also the words, "in an (or, the) epistle," could not have been added if he meant, "I have just written" (Co2 10:10). "His letters" (plural; not applying to merely one) confirm this. Co2 7:8 also refers to our first Epistle, just as here a former letter is referred to by the same phrase. Paul probably wrote a former brief reply to inquiries of the Corinthians: our first Epistle, as it enters more fully into the same subject, has superseded the former, which the Holy Spirit did not design for the guidance of the Church in general, and which therefore has not been preserved. See my Introduction.
1 Corinthians 5:10
co1 5:10Limitation of the prohibition alluded to in Co1 5:9. As in dissolute Corinth to "company with no fornicators," &c., would be almost to company with none in the (unbelieving) world; ye need not utterly ("altogether") forego intercourse with fornicators, &c., of the unbelieving world (compare Co1 10:27; Joh 17:15; Jo1 5:18-19). As "fornicators" sin against themselves, so "extortioners" against their neighbors, and "idolaters" against God. The attempt to get "out of the world," in violation of God's will that believers should remain in it but keep themselves from its evil, led to monasticism and its consequent evils.
1 Corinthians 5:11
co1 5:11But now--"Now" does not express time, but "the case being so," namely, that to avoid fornicators, &c., of the world, you would have to leave the world altogether, which would be absurd. So "now" is used in Heb 11:16. Thus we avoid making the apostle now retract a command which he had before given.
I have written--that is, my meaning in the letter I wrote was "not to keep company," &c.
a brother--contrasted with a "fornicator . . . of the world" (Co1 5:10). There is less danger in associating with open worldlings than with carnal professors. Here, as in Eph 5:3, Eph 5:5, "covetousness" is joined with "fornication": the common fount of both being "the fierce and ever fiercer longing of the creature, which has turned from God, to fill itself with the inferior objects of sense" [TRENCH, Greek Synonyms of the New Testament]. Hence "idolatry" is associated with them: and the covetous man is termed an "idolater" (Num 25:1-2). The Corinthians did not fall into open idolatry, but ate things offered to idols, so making a compromise with the heathen; just as they connived at fornication. Thus this verse prepares for the precepts in Co1 8:4, &c. Compare the similar case of fornication, combined with a similar idolatrous compromise, after the pattern of Israel with the Midianites (Rev 2:14).
no not to eat--not to sit at the same table with such; whether at the love-feasts (agapÃ&brvbr;) or in private intercourse, much more at the Lord's table: at the last, too often now the guests "are not as children in one family, but like a heterogeneous crowd of strangers in an inn" [BENGEL] (compare Gal 2:12; Jo2 1:10-11).
1 Corinthians 5:12
co1 5:12what have I to do--You might have easily understood that my concern is not with unbelievers outside the Church, but that I referred to those within it.
also--Implying, Those within give me enough to do without those outside.
do not ye, &c.--Ye judge your fellow citizens, not strangers: much more should I [BENGEL]. Rather, Is it not your duty to judge them that are within? God shall judge them that are without: do you look at home [GROTIUS]. God is the Judge of the salvation of the heathen, not we (Rom 2:12-16). Paul here gives an anticipatory censure of their going to law with saints before heathen tribunals, instead of judging such causes among themselves within.
1 Corinthians 5:13
co1 5:13put away from among yourselves that wicked--Sentence of excommunication in language taken from Deu 24:7.