John Gill's Exposition of the Whole Bible
Psalms 133:3
As the dew of Hermon, and as the dew that descended upon the mountains of Zion,.... Hermon was a very high hill beyond Jordan; the Sidonians called it Sirion, and the Amorites Shenir, Deuteronomy 3:8; hence Shenir and Hermon are mentioned together, Song of Solomon 4:8; and sometimes Sion or Seon, Deuteronomy 4:48; and is the Zion here intended; for the dew of Hermon could never descend on the mountain of Zion near Jerusalem, which was a hundred miles distant; besides Zion was but one mountain, these many. Hermon was remarkable for its dew, which still continues: a traveller c, one of our own country, and whose fidelity is to be depended on, lying in tents near this hill one night, says,
"we were sufficiently instructed by experience what the holy psalmist means by the dew of Hermon; our tents being as wet with it as if it had rained all night.''
The mountains of Zion were those that were near to Zion, and not the mountain itself, those that were round about Jerusalem, on which the dew also fell in great plenty; and to which unity among brethren is here compared, because it comes from God in heaven, as the dew does. Saints are taught of God to love one another; contentions and quarrels come from lusts within, but this comes from above, from the Father of lights; and, because of its gentle nature, this makes men pure, and peaceable, and gentle, and easy to be entreated; as the dew falls gently in a temperate and moderate air, not in stormy and blustering weather: and because of its cooling nature; it allays the heats and animosities in the minds of men; and because it makes the saints fruitful, and to grow and increase in good works;
for there the Lord commanded the blessing; either in the mountains of Zion; so Kimchi: and if Mount Zion is meant by it, the church, often signified thereby, is the dwelling place of the Lord; here he records his name and blesses; here his word is preached, which is full of blessings; and here ordinances are administered, which are blessed of God to his people. Theodoret thinks some respect is had to the pouring down of the Spirit on the apostles in Jerusalem, on the day of Pentecost: but rather the sense is, where brethren dwell together in unity, there the God of love and peace is; the Gospel of the grace of God is continued; and the ordinances of it made beneficial to the souls of men, they meeting together in peace and concord; see 2 Corinthians 13:11. God is said to "command the blessing" when he promises it, and makes it known to his people, or bestows it on them, Psalms 105:8;
[even] life for evermore: the great blessing of all, which includes all others, and in which they issue, the promise of the covenant, the blessing of the Gospel; which is in the hands of Christ, and comes through him to all his people; to the peacemakers particularly, that live in love and peace; these shall live for ever in a happy eternity, and never die, or be hurt of the second death.
c Maundrell's Travels, p. 57. Ed. 7.