Verses 1-3
In this Psalm, says Hengstenberg, “David brings to the consciousness of the church the glory of the fellowship of the saints, that had so long been wanting, the restoration of which had begun with the setting up of the Ark in Zion.” The Psalm, in fact, does not speak of the termination of the dispersion, but of the uniting of the people of all parts of the land for the purpose of divine worship in the one place of the sanctuary; and, as in the case of Psa 122:1-9, its counterpart, occasions can be found in the history of David adapted to the לדוד of the inscription. But the language witnesses against David; for the construction of שׁ with the participle, as שׁיּרד, qui descendit (cf. Psa 135:2, שׁעמדים, qui stant), is unknown in the usage of the language prior to the Exile. Moreover the inscription לדוד is wanting in the lxx Cod. Vat. and the Targum; and the Psalm may only have been so inscribed because it entirely breathes David's spirit, and is as though it had sprung out of his love for Jonathan.
With גּם the assertion passes on from the community of nature and sentiment which the word “brethren” expresses to the outward active manifestation and realization that correspond to it: good and delightful (Psa 135:3) it is when brethren united by blood and heart also (corresponding to this their brotherly nature) dwell together - a blessed joy which Israel has enjoyed during the three great Feasts, although only for a brief period (vid., Psa 122:1-9). Because the high priest, in whom the priestly mediatorial office culminates, is the chief personage in the celebration of the feast, the nature and value of that local reunion is first of all expressed by a metaphor taken from him. שׁמן הטּוב is the oil for anointing described in Exo 30:22-33, which consisted of a mixture of oil and aromatic spices strictly forbidden to be used in common life. The sons of Aaron were only sprinkled with this anointing oil; but Aaron was expressly anointed with it, inasmuch as Moses poured it upon his head; hence he is called par excellence “the anointed priest” (הכּהן המּשׁיה), whilst the other priests are only “anointed” (משׁחים, Num 3:3) in so far as their garments, like Aaron's, were also sprinkled with the oil (together with the blood of the ram of consecration), Lev 8:12, Lev 8:30. In the time of the second Temple, to which the holy oil of
