1-corinthians 10:30

For if I by grace be a partaker - Or rather, "If I partake by grace; if by the grace and mercy of God, I have a right to partake of this; yet why should I so conduct as to expose myself to the reproaches and evil surmises of others? Why should I lay myself open to be blamed on the subject of eating, when there are so many bounties of Providence for which I may be thankful, and which I may partake of without doing injury, or exposing myself in any manner to be blamed?"

Why am I evil spoken of - Why should I pursue such a course as to expose myself to blame or censure?

For that for which I give thanks - For my food. The phrase "for which I give thanks" seems to be a periphrasis for "food," or for that of which he partook to nourish life. It is implied that he always gave thanks for his food; and that this was with him such a universal custom, that the phrase "for which I give thanks" might be used as convenient and appropriate phraseology to denote his ordinary food. The idea in the verse, then, is this: "By the favor of God, I have a right to partake of this food. But if I did, I should be evil spoken of, and do injury. And it is unnecessary. God has made ample provision elsewhere for my support, for which I may be thankful. I will not therefore expose myself to calumny and reproach, or be the occasion of injury to others by partaking of the food offered in sacrifice to idols."

10:30 If I by grace am a partaker - If I thankfully use the common blessings of God.