What's the Oil & Dew of Psalm 133?

The Oil-It is like the precious ointment upon the head, that ran

down upon the beard, even Aaron's beard: that went down to the skirts of his garments;
Psalm 133:2
The Dew-As the dew of Hermon, and as the dew that descended upon the mountains of Zion:
Psalm 133:3

As nearly all Christians know, oil is a symbol for the Holy Spirit.
Dew is a symbol for the Word of God. 

My doctrine shall drop as the rain, 

My speech shall distil as the dew, 

as the small rain upon the tender herb, 

and as the showers upon the grass: 

Deuteronomy 32:2