For the sake of my brethren and neighbors. He specifies two causes on account of which he felt a care about the Church, for the purpose of stirring up, by his example, all the faithful to exercise the same care. These words, however, seem to contain a tacit contrast. Among the wicked and malicious he might be the object of suspicion, or, at least, he was in danger of being slandered; as if, in commending Jerusalem, he had rather an eye to his own particular advantage than to the public welfare. In order, therefore, to remove all ground for objecting, that in thus speaking he was craftily endeavoring to establish his own kingdom, he protests, that he is not influenced by personal considerations, but by a concern for the whole Church, which he embraced with a sincere affection of heart. I will speak, says he, O Jerusalem! of thy peace, not because it will be profitable for me or mine, but because thy prosperity shall extend itself to all the children of God; for under the term brethren he doubtless comprehends all believers that he did so, because the worship of God so far from remaining entire would go to ruin unless Jerusalem continued standing. If then the salvation of our brethren is regarded by us as an object of importance, if religion is with us a matter of heart-work, we ought, at the same time, as much as in us lies, to take an interest in the prosperity of the Church. Whence it follows, that such as are indifferent about her condition, are no less cruel than impious; for if she is "the pillar and foundation of truth," the inevitable consequence of her destruction must be the extinction of true piety. And if the body is destroyed, how can each of the members fail to be involved in destruction? Farther, this passage teaches us, that the Church is not an empty title, but must be sought for where the true religion prevails. Whence it appears, how foolish the Papists are, who, notwithstanding their having rejected and overthrown the doctrine of the Gospel, yet mightily boast of the name of the Church.

For my brethren and companions' sakes - Because they dwell there; or, because they go up there to worship; or, because they love thee, and find their happiness in thee; or, because they are unconverted, and all my hope of their salvation is to be derived from thee - from the church, from the influence of religion.
I will now say, Peace be within thee - I will pray for thy peace, for thy prosperity, for the blessing of God upon thee - because their good, their comfort, their hope of salvation, depends on thee - on the influence which shall go out from thee. So the Christian prays that the church may prosper - that the divine blessing may rest upon it - that there may be in it harmony, peace, love, and zeal - that a blessing may attend the preaching of the gospel - not only because he loves it, and seeks his own comfort and edification in it, but that his friends and kindred - his wife, his parents, his children, his neighbors - those whom he loves, and whose salvation he desires, may be saved. This expresses the true feelings of piety all over the world; this is one of the grounds of the strong love which the friends of God have for the church - because they hope and desire that through the church those most dear to their hearts will find salvation.

For any brethren and companions' sakes - Because this city is the abode of my kinsfolk and countrymen, I will wish it prosperity. I will promote its peace and tranquillity by all means in my power. I will affectionately say, May peace be within thee!

For my (g) brethren and companions' sakes, I will now say, Peace [be] within thee.
(g) Not only for my own sake but for all the faithful.

For my brethren and companions' sakes,.... Who were regenerated by the spirit of God; adopted into his family, and children of the same father; stood in the same relation to Christ the firstborn, and members of the same church; and so brethren: partners in the same blessings and promises of the covenant; partakers of the same grace; joined together in religious worship; shared in the same joys and griefs; travellers together to the same heavenly country, and entitled to the same glory and happiness. So David, though a king, reckoned his meanest subjects as such, who were spiritual men; and for their sakes, through the goodwill, love, and affection he bore to them, he would set praying souls an example, and by it enforce his own exhortation, as follows:
I will now say, peace be within thee; now and always put up this petition, and not put it off to longer time; that peace and prosperity may always attend the church of God, as well as the city of Jerusalem, literally considered, and the inhabitants of it.

In the welfare of the city, as its civil, and especially the religious relations, was involved that of Israel.
now--as in Psalm 115:2.