But if thou gloriest, thou bearest not the root, etc. The Gentiles could not contend with the Jews respecting the excellency of their race without contending with Abraham himself; which would have been extremely unbecoming, since he was like a root by which they were borne and nourished. As unreasonable as it would be for the branches to boast against the root, so unreasonable would it have been for the Gentiles to glory against the Jews, that is, with respect to the excellency of their race; for Paul would have them ever to consider whence was the origin of their salvation. And we know that after Christ by his coming has pulled down the partition-wall, the whole world partook of the favor which God had previously conferred on the chosen people. It hence follows, that the calling of the Gentiles was like an ingrafting, and that they did not otherwise grow up as God's people than as they were grafted in the stock of Abraham.

Boast not - The tendency of people is to triumph over one that is fallen and rejected. The danger of pride and boasting on account of privileges is not less in the church than elsewhere. Paul saw that some of the Gentiles might be in danger of exultation over the fallen Jews, and therefore cautions them against it. The ingrafted shoot, deriving all its vigor and fruitfulness from the stock of another tree, ought not to boast against the branches.
But if thou boast - If thou art so inconsiderate and wicked, so devoid of humility, and lifted up with pride, as to boast, yet know that there is no occasion for it. If there were occasion for boasting, it would rather be in the root or stock which sustains the branches; least of all can it be in those which were grafted in, having been before wholly unfruitful.
Thou bearest not the root - The source of all your blessings is in the ancient stock. It is clear from this, that the apostle regarded the church as one; and that the Christian economy was only a prolongation of the ancient dispensation. The tree, even with a part of the branches removed. and others ingrafted, retains its identity, and is never regarded as a different tree.

Boast not against the branches - While you are ready to acknowledge that you were included in the covenant made with Abraham, and are now partakers of the same blessings with him, do not exult over, much less insult, the branches, his present descendants, whose place you now fill up, according to the election of grace: for remember, ye are not the root, nor do ye bear the root, but the root bears you. You have not been the means of deriving any blessing on the Jewish people; but through that very people, which you may be tempted to despise, all the blessing and excellencies which you enjoy have been communicated to you.

(s) Boast not against the branches. But if thou boast, thou bearest not the root, but the root thee.
(s) We may rejoice in the Lord, but in such a way that we do not despise the Jews, whom we ought rather to encourage to join in the good battle with us.

Boast not against the branches,.... Those that were broken off: the apostle would not have them vaunt it over them, despise them, and trample upon them; but pity them, and pray for and be abundantly thankful and humbled before God, under a sense of Ida sovereign and distinguishing grace, who had settled them in a Gospel church state, who were before comparable to a wild olive tree; and much less should they glory over the believing Jews, among whom they were, there being no difference between them, for they were all one in Christ Jesus:
but if thou boast; but if such a vain temper of mind should prevail, he suggests they would do well to sit down and consider what little reason they had on their side to glory; and if such glorying and boasting, one against another was lawful, the Jews had the greatest reason for it; for, adds the apostle,
thou bearest not the root, but the root thee. The Jews received no advantages from the Gentiles, but on the contrary the Gentiles from the Jews, to whom were committed the oracles of God, and by whom they were faithfully kept and transmitted to the Gentiles; the Gospel itself came out first from among them; the first preachers of it were Jews, who carried it into the Gentile world, where it was greatly succeeded to the conversion of many, who by this means were brought into a Gospel church state, and so enjoyed all the privileges they did: yea, Christ himself, according to the flesh, came of them, was sent unto them, was the minister of them, lived and died among them, and wrought out the great salvation for his people; hence "salvation" itself is said to be "of the Jews", John 4:22, so that the root and foundation of all their enjoyments were from the Jews, and not those of the Jews from them; hence there was no room, nor reason, for boasting against them, and vaunting it over them.

Boast not against the--rejected
branches. But if thou--"do"
boast--remember that
thou bearest not--"it is not thou that bearest"
the root, but the root thee--"If the branches may not boast over the root that bears them, then may not the Gentile boast over the seed of Abraham; for what is thy standing, O Gentile, in relation to Israel, but that of a branch in relation to the root? From Israel hath come all that thou art and hast in the family of God; for "salvation is of the Jews" (John 4:22).

Boast not against the branches - Do not they do this who despise the Jews? or deny their future conversion?