Psalms 133:1

The prophet said in praise of fraternal charity: "Behold, how good and how pleasant it is for brethren to dwell together in unity." What good is there in the life of people except peace, in which upright pursuits make progress and religious activities are fostered? …

As a figure of this it is written in the Psalm: "Behold, how good and how pleasant it is for brethren to dwell together in unity. Like ointment upon the head, which descended upon the beard, the beard of Aaron." We have one Father, one …

They are blessed of God, and therefore blessed indeed: There, where brethren dwell together in unity, the Lord commands the blessing, a complicated blessing, including all blessings. It is God's prerogative to command the blessing, man can but beg a blessing. Blessings according to the promise are commanded blessings, for he has commanded his covenant for ever.

Behold, how good and how pleasant it is,....

Behold. It is a wonder seldom seen, therefore behold it! It may be seen, for it is the characteristic of real saints, —therefore fail not to inspect it! It is well worthy of admiration; pause and gaze upon it! It will charm you into imitation, therefore note it well! God looks on with approval, therefore consider it with attention. How good and holy pleasant it is for brethren to dwell together in unity! No one can tell the exceeding excellence of such a condition; and so the Psalmist uses the word "how" twice;—Behold how good! and how pleasant!

Behold. It is a wonder seldom seen, therefore behold it! It may be seen, for it is the characteristic of real saints, —therefore fail not to inspect it! It is well worthy of admiration; pause and gaze upon it! It will charm you into imitation, therefore note it well! God looks on with approval, therefore consider it with attention. How good and holy pleasant it is for brethren to dwell together in unity! No one can tell the exceeding excellence of such a condition; and so the Psalmist uses the word "how" twice;—Behold how good! and how pleasant! He does not attempt to measure either the good or the pleasure, but invites us to behold for ourselves. The combination of the two adjectives "good" and "pleasant", is more remarkable than the conjunction of two stars of the first magnitude: for a thing to be "good" is good, but for it also to be pleasant is better. All men love pleasant things, and yet it frequently happens that the pleasure is evil; but here the condition is as good as it is pleasant, as pleasant as it is good, for the same "how" is set before each qualifying word. For brethren according to the flesh to dwell together is not always wise; for experience teaches that they are better a little apart, and it is shameful for them to dwell together in disunion. They had much better part in peace like Abraham and Lot, than dwell together in envy like Joseph's brothers. When brethren can and do dwell together in unity, then is their communion worthy to be gazed upon and sung of in holy Psalmody. Such sights ought often to be seen among those who are near of kin, for they are brethren, and therefore should be united in heart and aim; they dwell together, and it is for their mutual comfort that there should be no strife; and yet how many families are rent by fierce feuds, and exhibit a spectacle which is neither good nor pleasant!

Behold, how good and how pleasant - Unity is, according to this scripture, a good thing and a pleasant; and especially among brethren - members of the same family, of the same Christian community, and of the same nation. And why not among the great family of mankind? On the other hand, disunion is bad and hateful. The former is from heaven; the latter, from hell.

Behold - As if he looked upon such a gathering, and saw there the expressions of mutual love. This may have been uttered in the actual contemplation of such an assemblage; or it may have been a picture of the imagination. How good - How good in itself; how proper; how suited to promote happiness, and to diffuse good influences abroad. And how pleasant - The word used here means lovely, charming, attractive; that which fills the mind with delight, spoken of one beloved, Son 7:6; of a friend, 2Sa 1:26; of a place, Gen 49:15; of words, Pro 15:26; of beauty or glory, as of Yahweh, Psa 27:4. It is descriptive of the pleasure which we derive from a picture, from a landscape, from sweet sounds and gentle voices, or from love. For brethren to dwell together in unity - Margin, even together. Hebrew, “The dwelling of brethren also together.” Perhaps the idea in the word “also” may be, that while the unity of brethren when separate, or as they were seen when scattered in their habitations, was beautiful, it was also pleasant to see them when actually assembled, or when they actually came together to worship God. As applicable to the church, it may be remarked (1) that all the people of God - all the followers of the Redeemer - are brethren, members of the same family, fellow-heirs of the same inheritance, Mat 23:8. (2) There is a special fitness that they should be united, or dwell in unity. (3) There is much that is beautiful and lovely in their unity and harmony. They are redeemed by the same Saviour; they serve the same Master; they cherish the same hope; they are looking forward to the same heaven; they are subject to the same trials, temptations, and sorrows; they have the same precious consolations. […]

I've learned that broken covenants impact your spiritual authority because disunity diminishes the anointing (Ps. 133) and creates conditions for the curse.