John Chrysostom

"Boast not against the branches." He seems indeed to be comforting the Jew, but points out his vileness and extreme dishonor. And this is why he says not, "boast not," but, "boast not against" do not boast against them so as to sunder them. For it is into their place that ye have been set, and their goods that ye enjoy. Do you observe how he seems to be rebuking the one, while he is sharp upon the other? "But if thou boast," he says, "thou bearest not the root, but the root thee."

Now what is this to the branches that are cut off? Nothing. For, as I said before, while seeming to devise a sort of weak shadow of consolation, and in the very midst of his aiming at the Gentile, he gives them a mortal blow; for by saying, "boast not against them," and, "if thou boast, thou bearest not the root," he has shown the Jew that the things done deserved boasting of, even if it was not right to boast, thus at once rousing him and provoking him to faith, and smiting at him, in the attitude of an advocate, and pointing out to him the punishment he was undergoing, and that other men had possession of what were their goods.