Vincent's Word Studies, by Marvin R. Vincent, [1886], at sacred-texts.com
Things offered unto idols (εἰδωλοθύτων)
See on Rev 2:14.
We know that we all, etc.
The arrangement of the text is in question. Evidently a parenthesis intervenes between the beginning of Co1 8:1 and Co1 8:4. It seems best to begin this parenthesis with knowledge puffeth up, and to end it with known of him (Co1 8:3).
We all have knowledge (πάντες γνῶσιν ἔχομεν)
The exact reference of these words must remain uncertain. Some understand Paul himself and the more enlightened Corinthians. Others, all Christians. All the expositions are but guesses. I prefer, on the whole, the view that Paul is here repeating, either verbally or in substance, a passage from the letter of the Corinthians to him. In that case the sense is slightly ironical: "We know, to use your own words, that we all have knowledge." The parenthesis thus comes in with an appropriate cautionary force.
Puffeth up
See on Co1 4:6. The contrast is striking between puffing up and building up - a bubble and a building.
That he knoweth anything (ἐγνωκέναι τι)
Or, literally, has come to know. See on Joh 2:24; see on Joh 3:10; see on Joh 17:3. Showing in what sense knowledge was used in the previous clause: fancied knowledge; knowledge of divine things without love.
The same is known of Him (οὗτος ἔγνωσται ὑπ' αὐτοῦ)
The same, i.e., this same man who loves God. He does not say knows God, but implies this in the larger truth, is known by God. Compare Gal 4:9; Jo1 4:7, Jo1 4:8, Jo1 4:16; Ti2 2:19. Γινώσκω in New-Testament Greek often denotes a personal relation between the knower and the known, so that the knowledge of an object implies the influence of that object upon the knower. So Joh 2:24, Joh 2:25; Co1 2:8; Jo1 4:8. In John the relation itself is expressed by the verb. Joh 17:3, Joh 17:25; Jo1 5:20; Jo1 4:6; Jo1 2:3, Jo1 2:4, Jo1 2:5.
An idol is nothing in the world (οὐδὲν εἴδωλον ἐν κόσμῳ)
Rev., no idol is anything. An idol is a nonentity. The emphasis is on the nothingness of the idol, hence the emphatic position of οὐδὲν nothing. It is a mere stock or stone, having no real significance in heaven or on earth. One of the Old Testament names for heathen gods is elilim nothings. Idol (εἴδωλον) is primarily an image or likeness. In Greek writers it is sometimes used of the shades of the dead, or the fantasies of the mind. In the Old Testament, the number and variety of the words representing the objects of heathen worship, are a striking commentary upon the general prevalence of idolatry. Εἴδωλον image stands in the Septuagint for several of the different Hebrew terms for idols; as, elilim things of nought; gillulim things rolled about, as logs or masses of stone; chammanium sun-pillars, etc. Other words are also used to translate the same Hebrew terms, but in all cases the idea is that of the material object as shaped by mechanical processes, or as being in itself an object of terror, or a vain or abominable thing, a mere device of man.
Gods - lords
Superhuman beings to whom these titles are given, as Eph 6:12; Co2 4:4; Joh 12:31; Joh 14:30.
With conscience of the idol (τῇ συνειδήσει τοῦ εἰδώλου)
The best texts read συνηθείᾳ custom, which occurs only here and Joh 18:39; see note. Lit., with custom of the idol; i.e., as Rev., being used to the idol. Their long habit previous to their conversion made them still regard their offering as made to something really existent, and consequently to feel that it was sinful to eat of meat thus offered.
Is defiled (μολύνεται)
See on Rev 14:4.
Commendeth - not (οὐ παραστήσει)
Lit., present. Rev., more correctly, will not commend. See on shewed himself, Act 1:3.
Stumbling-block (προσκόμμα)
See on Rom 14:13.
Idol's temple (εἰδωλείῳ)
Only here in the New Testament. See on Rev 2:14.
Be emboldened (οἰκοδομηθήσεται)
Lit., be built up. The A.V. misses the irony of the expression. His apparent advance is really detrimental. Calvin remarks: "a ruinous upbuilding."
Shall the weak brother perish (ἀπόλλυται ὁ ἀσθενῶν)
Not a question, as A.V. The participle "he that is being weak" indicates a continuance of the weakness, and the present tense, is perishing, implies that the process of moral undermining is in progress through the habitual indulgence of the better informed Christian. Rev., he that is weak perisheth.
Make to offend (σκανδαλίζει)
See on Mat 5:29. Rev., maketh to stumble.
Meat - flesh (βρῶμα - κρέα)
The former food in general, the latter the special food which causes stumbling. Dr. South draws the distinction between a tender and a weak conscience. "Tenderness, applied to the conscience, properly imports quickness and exactness of sense, which is the perfection of this faculty .... Though the eye is naturally the most tender and delicate part of the body, yet is it not therefore called weak, so long as the sight is quick and strong.... A weak conscience is opposed to a strong; which very strength, we shew, consisted in the tenderness or quickness of its discerning or perceptive power" (Sermon 29, "A True State and Account of the Plea of a Tender Conscience").