8:7-13 Eating one kind of food, and abstaining from another, have nothing in them to recommend a person to God. But the apostle cautions against putting a stumbling-block in the way of the weak; lest they be made bold to eat what was offered to the idol, not as common food, but as a sacrifice, and thereby be guilty of idolatry. He who has the Spirit of Christ in him, will love those whom Christ loved so as to die for them. Injuries done to Christians, are done to Christ; but most of all, the entangling them in guilt: wounding their consciences, is wounding him. We should be very tender of doing any thing that may occasion stumbling to others, though it may be innocent in itself. And if we must not endanger other men's souls, how much should we take care not to destroy our own! Let Christians beware of approaching the brink of evil, or the appearance of it, though many do this in public matters, for which perhaps they plead plausibly. Men cannot thus sin against their brethren, without offending Christ, and endangering their own souls.
10. if any man—being weak.
which hast knowledge—The very knowledge which thou pridest thyself on (1Co 8:1), will lead the weak after thy example to do that against his conscience, which thou doest without any scruple of conscience; namely, to eat meats offered to idols.
conscience of him which is weak—rather, "His conscience, seeing he is weak" [Alford and others].
emboldened—literally, "built up." You ought to have built up your brother in good: but by your example your building him up is the emboldening him to violate his conscience.