The 'vav' is the 6th letter and denotes the human brain connected to the human spine. It is the 6th letter just as man was created on the 6th day of creation.
The Hebrew Torah (books of Moses) can not be understood properly unless read in the original Hebrew - much of it has been mistranslated when rendered into other languages such as English.
For example Genesis or 'generation' is not an historical text - it attempts to describe the process of creation from the inside out, not outside in as literal renditions and readers interpret.
'Light', as made on the first day, is essentially the basis of all creation: its nonphysical counterpart being 'truth' as the Hebrew terms for 'light' and 'skin' are the same word with one letter changed signifying the difference in perspective as 'inside-out' and 'outside-in'.
The expression adopted by Christian 'Truth (of the) Way (of) Life' associated to/with the Greek mythologies and character of Jesus is a universal axiom that describes the relationship the brain (truth / Father) has with the heart (way / Son) and with the sex (life / Holy Spirit). These three components of the human mechanism (intellectual brain / emotional brain / motor-instinctual (sexual) brain) comprise the 'trinity' wherein the only way to 'truth' (the Father - Hebrew term 'kether') is through wisdom (the Son - Hebrew term 'chokmah') which comes from understanding (Hebrew term 'binah').
People that eat from the tree of the knowledge of good and evil (Hebrew term 'autz hayim') generate the 'us' vs. 'them' worldview which is the source of conflict/death. This principle division existed within Christianity 'believer vs. unbeliever' and still exists in Islam which continues to this day to deny the trinity (relationship between brain-heart-sex).