Vav — the 6th Hebrew letter
ו
Symbolism
Connection, and-ness; the nail that joins; six — the number of man (created day six) and of physical space (six directions)
What the letter is built from
A single straight line — the letter is its own part: a nail, a tent peg, a connector
Its first root in Scripture
Almost no Hebrew roots begin with vav — the first is vav itself: the hooks that held up the Tabernacle curtains
Messianic thread
The letter of the nail, whose value is six, the number of man — Messianic readers see the vav of connection pierced into the Man of the sixth day's redemption. The broken vav of shalom (Num 25:12) and the missing vav of Elijah wait for wholeness.
In the mystical tradition
Vav is the hook joining heaven and earth, the 'and' that binds every phrase of Torah; the vav of the Name channels the upper heh to the lower.
Wisdom of the letter
Nearly every verse of Torah begins with vav — Scripture is one long connected sentence, each line nailed to the one before.