IT is natural to suppose that this psalm was occasioned by, or at least refers to, the gathering of the pilgrims or restored exiles in Jerusalem. The patriot-poet’s heart glows at the sight of the assembled multitudes, and he points with exultation to the good and fair sight. Like the other short psalms in this group, this one is the expression of a single thought-the blessing of unity, and that not merely as shown in the family, but in the church state of the restored Israel. The remembrance of years of scattering among the nations, and of the schism of the Northern tribes, makes the sight of a united Israel the more blessed, even though its numbers are small.
The psalm begins with a "Behold," as if the poet would summon others to look on the goodly spectacle which, in reality or in imagination, is spread before him. Israel is gathered together, and the sight is good, as securing substantial benefits, and "pleasant," as being lovely. The original in Psalms 133:1 b runs, "That brethren dwell also together." The "also" suggests that, in addition to local union, there should be heart harmony, as befits brothers. To speak in modern dialect, the psalmist cares little for external unity, if the spirit of oneness does not animate the corporate whole.
His two lovely metaphors or parables set forth the same thought-namely, the all-diffusive, all-blessing nature of such inward concord. The repetition in both figures of the same word, "flows down," is not merely due to the "step-like" structure common to this with other of the pilgrim psalms, but is the key to its meaning.
In the first emblem, the consecrating oil, poured on Aaron’s head, represents the gracious spirit of concord between brethren. The emblem is felicitous by reason of the preciousness, the fragrance, and the manifold uses of oil; but these are only to be taken into account in a subordinate degree, if at all. The one point of comparison is the flow of the oil from the priestly head on to the beard and thence to the garments. It is doubtful whether Psalms 133:2 d refers to the oil or to the beard of the high priest. The latter reference is preferred by many, but the former is more accordant with the parallelism, and with the use of the word "flows down," which can scarcely be twice used in regard to oil and dew, the main subjects in the figures, and be taken in an entirely different reference in the intervening clause. The "opening" (lit. mouth) of the robe is the upper edge or collar, the aperture through which the wearer’s head was passed.
The second figure illustrates the same thought of the diffusive blessing of concord, but it presents some difficulty. How can the dew of Hermon in the far north fall on the mountains of Zion? Some commentators, as Delitzsch, try to make out that "an abundant dew in Jerusalem might rightly be accounted for by the influence of the cold current of air sweeping down from the north over Hermon." But that is a violent supposition; and there is no need to demand meteorological accuracy from a poet. It is the one dew which falls on both mountains; and since Hermon towers high above the lower height of Zion, and is visited with singular abundance of the nightly blessing, it is no inadmissible poetic licence to say that the loftier hill transmits it to the lesser. Such community of blessing is the result of fraternal concord, whereby the high serve the lowly, and no man grudgingly keeps anything to himself, but all share in the good of each. Dew, like oil, is fitted for this symbolic use, by reason of qualities which, though they do not come prominently into view, need not be wholly excluded. It refreshes the thirsty ground and quickens vegetation; so fraternal concord, falling gently on men’s spirits, and linking distant ones together by a mysterious chain of transmitted good, will help to revive failing strength and refresh parched places.
That brotherly unity is blessed, not only because it diffuses itself, and so blesses all in whose hearts it dwells, but also because it is the condition on which still higher gifts are spread among brethren by their brethren’s mediation. God Himself pours on men the sacred anointing of His Divine Spirit and the dew of His quickening influences. When His servants are knit together, as they should be, they impart to one another the spiritual gifts received from above. When Christians are truly one as brethren, God’s grace will fructify through each to all.
Psalms 133:3 b, c, seem to assign the reason why the dew of Hermon will descend on Zion-i.e., why the blessings of brotherly concord should there especially be realised. There God has appointed to be stored His blessing of life; therefore it becomes those who, dwelling there, receive that blessing, to be knit together in closest bonds, and to impart to their brethren what they receive from the Fountain of all good. That Zion should not be the home of concord, or that Jerusalem should not be the city of peace, contradicts both the name of the city and the priceless gift which Jehovah has placed there for all its citizens.