I know - This is an admission made to the “Gentile” convert, who believed that it was lawful to partake of food of every kind. This the apostle concedes; and says he is fully apprized of this. But though he knew this, yet he goes on to say Romans 14:15, that it would be well to regard the conscientious scruples of others on the subject. It may be remarked here that the apostle Paul had formerly quite as many scruples as any of his brethren had then. But his views had been changed.
And am persuaded - Am convinced.
By the Lord Jesus - This does not mean by any “personal” instruction received from the Lord Jesus, but by all the knowledge which he had received by inspiration of the nature of the Christian religion. The gospel of Jesus had taught him that the rites of the Mosaic economy had been abolished, and among those rites were the rules respecting clean and unclean beasts, etc.
There is nothing unclean - Greek “common.” This word was used by the Jews to denote what was “unclean,” because, in their apprehension, whatever was partaken by the multitude, or all people, must be impure. Hence, the words “common” and “impure” are often used as expressing the same thing. It denotes what was forbidden by the laws of Moses.
To him that esteemeth ... - He makes it a matter of conscience. He regards certain meats as forbidden by God; and while he so regards them, it would be wrong for him to partake of them. Man may be in error, but it would not be proper for him to act in violation of what he “supposes” God requires.