Whatsoever is sold in the shambles, that eat, asking no question for conscience sake: Whatsoever is sold in the shambles, that eat - The case to which the apostle refers is simply this; it was customary to bring the flesh of the animal to market, the blood of which had been poured out in sacrifice to an idol; or, taken more particularly, the case was this; one part of the sacrifice was consumed on the altar of the idol: a second part was dressed and eaten by the sacrificer; and a third belonged to the priest, and was often sold in the shambles. To partake of the second share, or to feast upon the sacrifice, St. Paul absolutely forbids, because this was one part of the religious worship which was paid to the idol; it was sitting down as guests at his table, in token that they were in fellowship with him. This was utterly incompatible with receiving the sacrament of the Lord's Supper, which was the communion of the body and blood of Christ. But as to the third share, the apostle leaves them at liberty either to eat of it or forbear; except that, by eating, their weak brethren should be offended; in that case, though the thing was lawful, it was their duty to abstain. See the notes on 1 Corinthians 8:1, etc. Hindoos eagerly embrace whatever has been offered to an idol: hence it is common to see the flowers that have been thus offered placed in the hair of a Hindoo. Water that has been thus made sacred is preserved in Hindoo houses, and with it they rub their bodies, and occasionally sip a drop, regarding it as the water of life. - See Ward.
Asking no questions for consciences sake - Dr. Lightfoot observes, that "the Jews were vexed with innumerable scruples in their feasts, as to the eating of the thing, as well as to the company with which they ate; and even the manner of their eating. Of fruits and herbs brought to the table, they were to inquire whether they were tithed according to custom; whether they were consecrated by the Truma, or whether they were profane; whether they were clean, or touched with some pollution, etc. And concerning flesh set on the table, they were to inquire whether it was of that which had been offered to idols; whether it were the flesh of an animal that had been torn by wild beasts; or of that which had been strangled, or not killed according to the canons; etc., etc. All which doubts the liberty of the Gospel abolished as to one's own conscience, with this proviso, that no scandal or offense be cast before another man's weak or scrupulous conscience."
From this it is evident that the apostle had the case of the Jewish converts in view, and not the Gentiles. The latter were not troubled with such extraordinary scrupulousness.