The family-unity of God's people

Psalm 133:1-3
How good and pleasant it is when God’s people live together in unity!
It is like precious oil poured on the head, running down on the beard, running down on Aaron’s beard, down on the collar of his robe.
It is as if the dew of Hermon were falling on Mount Zion. For there the Lord bestows(賜給) his blessing, even life forevermore.
This is a 'wisdom' psalm. The theme is the family harmony of God's people, precious as holy oil or dew fall on bare hills.
Why?
It is honored the name of the Lord by David.
God's people live together in unity is good and pleasant.
Precious oil poured on the head... is the Holy Spirit come down so is the blessing of God with us.
Dew of Hermon falling on Mount Zion, mean the blessing of the Lord come give his people prosperity and life forevermore.
How?
Brother and sister in church live together in unity is very good and pleasant things.