&c. If the first-fruit (see the Greek word) be holy, so also is the mass; so also the rest, the product that follows. He alludes to the offering made by the law of the first-fruit, which was to acknowledge that all good things were from God, and to bring a blessing upon the rest.

If the root be holy, so are the branches. By the root, says St. Chrysostom, he understands Abraham, and the patriarchs, from whom all the Jewish nation proceeded, as branches from that root: and these branches are to be esteemed holy, not only because of the root they proceeded from, but also because they worshipped the true God. And if some, or a great part of these branches, have been broken, they may, as it is said, (ver. 23.) be ingrafted again. And you, Gentiles, ought to remember that, you were of yourselves a wild olive-tree: and it is only by the merciful call of God, that you have the happiness to be ingrafted upon the same root of the patriarchs; and so, by imitating the faith of Abraham, are become his spiritual children, and heirs of the promises, and by that means have been made partakers of the root, and of the sap, and fatness of the sweet olive-tree. Remember that you bear not the root, nor were you the root that was holy; but the root beareth you; and that being branches of a wild olive, you ought naturally still to bear bad fruit, though ingrafted on the root of a sweet olive. It is only by the mercies of God, if you bring forth good fruit. Do not then be high-minded, nor boast, but fear, and endeavour to continue in goodness; lest God also spare not you, but cut you off, as unprofitable branches. And let me tell you, as to the Jews, if they abide not still in unbelief, God is able to ingraft them again into their own olive-tree; and it seems more easy, that they, who are naturally branches of the sweet olive-tree, should bring forth good fruit, when they shall be ingrafted in their own olive-tree, being of the race of Abraham, to whom the promises were made. (Witham)

We see here, that he who standeth by faith, may fall from it; and therefore must live in fear, and not in the vain presumption and security of modern sectaries. (Challoner)

The apostle here exhorts the converted Gentiles, to fear lest they fall, and bring upon themselves a punishment similar to that of the Jews. The Jews were his chosen people, the children of the alliance; they have now been stripped of all; the same may also happen to you. You may fall into presumption and incredulity; if you remain firm, it is not by your own merits or works, but by faith, the pure gift of God. Neither faith, nor vocation, nor grace, are inadmissible. You may lose all; and therefore ought always to fear and live in humility. If God has not spared the natural branches, fear, lest he should not spare you. (ver. 21.) (Calmet)

The Gentiles are here admonished not to be proud, nor to glory over the Jews; but to take occasion rather from their fall to fear and to be humble, lest they be cast off. Not that the whole Church of Christ can ever fall from him; having been secured by so many divine promises in holy writ; but that each one in particular may fall; and therefore all in general are to be admonished to beware of that, which may happen to any one in particular. (Challoner)