Hebrew letter Shin has three prongs and represents the indivisible
unity of G-d, Torah, and Israel. On the Tree of Life it represents
"Hokhmah" or wisdom and is located in the right
hemisphere of the brain. Wisdom comes from the Holy One in
a flash and is indivisible and indescribable.
left hemisphere of the brain, however, is created by G-d in
order to "figure things out" and to to attempt to
divide the indivisible and to describe that which is beyond
words. This gift is called "Binah" and translates
into English as understanding. In Kabbalah it is represented
by the Shin with four prongs, as represented here. Why four?
Because four is a divisible number and represents the aspect
of intellect which is linear, orderly, and verbal.
two Shins represent the male and female energies that Hashem
has created. The three-pronged Shin is for Abraham, Isaac,
and Jacob. The four-pronged Shin is for Sarah, Rebecca, Rachel,
and Leah. There are thirteen letters in the names of the patriarchs
(Abraham, Issac, and Jacob) in Hebrew, and there are thirteen
letters in the names of the matriarchs (Sarah, Rebecca, Rachel,
and Leah). G-d's most holy name (called the Tetragrammaton)
has the gematria (numerical value) of twenty-six which is
the unity of the fathers and mothers, the masculine and feminine
principles in the universe. Finally, four and three add up
to seven which represents completion and totality as in the
days of the week.