Albert Barnes Commentary 1 Corinthians 8:9

"But take heed lest by any means this liberty of yours become a stumblingblock to the weak." — 1 Corinthians 8:9 (ASV)

But take heed. This is Paul's reply to the argument of the Corinthians in 1 Corinthians 8:8. "Though all that you say should be admitted to be true, as it must be; though a person is neither morally better nor worse for eating meat or abstaining from it; yet the grand principle to be observed is to act so as not to injure your brothers. Though you may be no better or worse for eating or not eating, yet, if your conduct will injure others and lead them into sin, that is a sufficient guide to determine what you should do in the case. You should abstain entirely. It is far more important that your brother should not be led into sin than it is that you should eat meat which you acknowledge (1 Corinthians 8:8) is in itself of no importance."

Lest by any means. mhpwv. You should be careful that by no conduct of yours your brother be led into sin. This is a general principle that is to regulate Christian conduct in all matters that are in themselves indifferent.

This liberty of yours. This which you claim as a right; this power which you have, and the exercise of which is in itself lawful. The liberty or power (exousia) referred to here was that of eating the meat that was offered in sacrifice to idols (1 Corinthians 8:8). A person may abstractly have a right to do a thing, but it may not be prudent or wise to exercise it.

Become a stumbling-block. An occasion of sin. (See commentary on Matthew 5:29).

Ensure it does not become the occasion of leading others to sin and to abandon their Christian profession (1 Corinthians 8:10).

To them that are weak. To those professing Christians who are not fully informed or instructed regarding the true nature of idolatry, and who may still have a superstitious regard for the gods whom their fathers worshipped.