To the weak became I as weak
That is, to weak Christians, who were weak in faith, and had not such clear knowledge of Gospel liberty, and therefore scrupled the eating of some sorts of meat, and particularly meats offered to idols; and the apostle so far consulted the peace and edification of these weak brethren, and so far complied with them, and became as one of them, that, rather than offend them, he determined to eat no meat while the world stood:
that I might gain the weak;
promote their edification and welfare, who otherwise might be stumbled, be in danger of falling from, and laid under a temptation to desert the faith of the Gospel:
I am made all things to all men;
which is to be understood, as in all the other instances of his being so, not in cases and things criminal and sinful, contrary to the moral law, and the dictates of his own conscience, subversive of the Gospel of Christ, and of the order and discipline of it, but in cases and things of an indifferent nature:
that I might by all means save some;
that is, that he might be the means of saving some of Jews and Gentiles, and of all sorts of men; by preaching the Gospel of salvation to them, and by directing them to Christ, the only Saviour of lost sinners; thus he explains what he means by so often saying that he might gain them.