[It is] like the precious ointment upon the head,.... The composition which Moses was ordered to make of the principal spices, and therefore called precious; and which was poured on the heads of kings and priests, when they were anointed with it, Ex 30:23;that ran down upon the beard, [even] Aaron's beard; this was put upon the head of Aaron when he was anointed, and so on any other high priest, and trickled down to his beard; see Ex 29:7.
The reasons Kimchi and Ben Melech give, why the anointing of Aaron and other priests is mentioned, and not the anointing of a king, or of David himself, are, because the anointing of Aaron was first, and also more public and better known by the people;that went down to the skirts of his garments; or, "the mouth" or "opening of his garments" ; not the extremity of them, as our version inclines to; for not so great a quantity of oil was poured upon him; nor would it have been decent to have his clothes thus greased from top to bottom: but the upper part of his garment, the top of the coat, on which the beard lay, as Jarchi; the neck or collar of it, as Kimchi and Ben Melech; the hole in which the head went through when it was put on, about which there was a band, that it might not be rent, Ex 28:32; where the Septuagint use the same word as here.
Suidas says, David means the superior aperture of the garment, that which we call the neck or collar band; and so Theodoret: and the Arabic version renders it, the "aperture", or opening of it; and hitherto the ointment came.
This was typical of the grace of the Spirit, the unction from the Holy One; which has been poured on Christ, the head of the church, without measure; and with which he has been anointed above his fellows; and from him it is communicated to all his members; to every one of which is given grace, according to the measure of the gift of Christ; and who from his fulness receive, and grace for grace: and particularly brotherly love is compared to this ointment; because of the preciousness of it, which is true of every grace; and because of the extensiveness of it, reaching to head and members, to Christ and all his saints, the meanest and lowest of them; and because of its fragrancy and sweet odour to all that are sensible of it; and because of its delightful, cheering, and refreshing nature; like ointment and perfume it rejoices the heart; yea, the worst things said, or reproofs given, in brotherly love, are like oil, pleasant and useful, Pr 27:9; and is as necessary for the saints, who are all priests unto God, to offer up their spiritual sacrifices; particularly that of prayer, which should be "without wrath", as well as without doubting; and to do all other duties of religion, which should spring from charity or love; as the anointing oil was to Aaron and his sons, in order to their officiating in the priest's office.
yp le epi thn wan, Sept. "super os", Montanus, Piscator; "super os, vel aperturam", Michaelis; "in capitium", Tigurine version; "upon the collar of his garments", Ainsworth.