Albert Barnes Commentary Psalms 133:2

"It is like the precious oil upon the head, That ran down upon the beard, Even Aaron`s beard; That came down upon the skirt of his garments;" — Psalms 133:2 (ASV)

It is like the precious ointment upon the head - This refers to the ointment that was poured upon the head of the high priest when consecrated to the holy office. The Hebrew is, “the good ointment.” For a description of the ointment used in the consecration of the high priest and the holy things of the sanctuary, see Exodus 30:22-30.

Compare the notes at Isaiah 61:3, on the phrase oil of joy. Anointing with oil was common on festivals and joyous occasions (see the notes at Psalm 23:5). Consequently, it became an emblem of anything joyous, happy, and beautiful. This idea seemed to reach its highest expression when connected with the anointing of a high priest for the sacred duties of his office.

The only resemblance between the idea of anointing with oil and that of harmony among brethren is derived from the gladness—the joyousness—connected with such an anointing.

The psalmist sought to convey the highest idea of the pleasantness of such harmony; and he therefore compared it with that which was most beautiful to a pious mind—the idea of a solemn consecration to the highest office of religion. The comparison is one which would not unnaturally occur to a Jew.

That ran down upon the beard - Descending from the head upon the long, flowing beard. The idea here is that of copiousness or abundance—as if so much ointment was poured out as to descend on the whole person, consecrating the entire man.

Even Aaron’s beard - The word “even” here, introduced by our translators, weakens the force and beauty of the comparison. The psalmist had the simple image of Aaron before his mind, without intending to compare him with any other.

That went down to the skirts of his garments - literally, “to the mouth of his garment.” The idea is that the anointing oil was abundant enough to flow down so as to fall on his entire robe, diffusing a sweet fragrance all around.

It is possible, though it may seem like a fanciful notion, that the psalmist may have had an idea of unity in this, as if in the anointing of the high priest the whole man was consecrated, or was “united” in the consecration.

It was not merely the head, but the beard, his garments, and the entire person, that shared in the fragrance of the anointing oil. Thus, love in a Christian community is so abundant—so overflowing—that it spreads over all the spiritual body, the church; the same sweet and holy influence, represented by the oil of anointing, pervades all and combines all in one.