Quf is one of the 12 Simple Letters: Time.
It is the nineteenth letter of the Hebrew Alphabet. Its numerical value is 100.
Quf corresponds to the twelfth diagonal path of the Tree of Life, the path which connects Bina to Hesed.
Sepher Yetzirah says about Quf: “… He made the letter Quf king over laughter, and He bound a crown to it, and He combined one with another, and with them He formed Pisces in the Universe, Adar in the Year, and the spleen in the Soul male and female.”
Quf corresponds to the Astrological Sign of Pisces.
Quf is the will to go down to the evil, the confrontation with the dark, and the encounter with the Leviathan, the biblical sea monster (Job 41:1~34). The Leviathan corresponds to the collective unconscious.
Quf is the graphical representation of the descent to hell. Kabbalah says that God has given to Quf the power to go up again after its fall. This power is called Teshuvà (תשובה, meaning return, conversion): the capacity to fall and get back.
100 corresponds to 10 x 10, the 10 Sephiroth multiplied by themselves. In Kabbalah, the square of a number is the maximum expression of all its qualities. This concept is called Hitkalelut (התכללות, meaning inter-inclusion, intermingling), by which each Sephira contains within it all of the other Sephiroth: the perfect beauty.
Quf is teaching us the power of conversion in our lives: it does not matter how deep one can fall if it finds the strength to climb again, and save the others.