The letter CHET

Chet is the letter of life חיים.
It represents infinite possibilities. It is undifferentiated substance and energy, containing all the possibilities that could come into being. 

Chet indicates the ability of the human to rise and go beyond nature. It is related to the Neshama, the soul. It represents the power of choice which is given by the soul, as well as the qualities of charm and grace חן which stem from the soul.

Chet is like a revolving gateway, a power to enter a higher level, to enter the mysteries of one’s soul, and then return to worldly consciousness. The ancient form of the letter looks like a ladder, indicating the ability to go above and beyond limitations. And as the letter for 8, it also signifies transcending nature, as represented by the 7 days of creation.
It is the essence of the human being to break through nature, to spiritual realization. It is also in the word for prophecy hazon חזון, and wisdom hochmah חוכמה.

"Chet" is the letter of life (chaim, from the root chayah, whose most important letter is chet). We are taught in Chassidut that there are two levels of life "essential life" and "life to enliven." G-d Himself, as it were, is in the state of "Essential life." His creative power, continually permeating all of reality is "life to enliven." So in the Jewish soul: the essence of its root, at one with G-d, possesses the state of "essential life." The reflection of the light of the soul which shines below to enliven the body and its physical experience is at the level of "life to enliven." The second level of life, life as we know it in general, manifests itself as pulsation, the secret of "run and return." 

According to the Ari z"l," the letter chet is constructed by combining the two previous letters, vav and zayin, with a thin bridgeshaped line, referred to as the chatoteret ("hunchback"). The new energy effected by the union of the vav--or yashar--and the zayin--or chozer--is the secret of "hovering" or "touching yet not touching." The image of "hovering" appears at the very beginning of Creation: "And the spirit of G-d was 'hovering' over the water." The word "hovering" (merachefet) is the eighteenth word in the Torah. It is the first word in the Torah which is numerically a multiple of twenty-six, the value of the Name Havayah (merachefet = 728 = 26 times 28). Twentyeight is the numerical value of koach, "power." Thus, the full secret implied by the numerical value of the word "hovering" is "the power of G-d." In Kabbalah, this word is, in particular, the secret of the Divine power to resurrect the 288 fallen sparks that "died" in the process of the "breaking of the vessels" (merachefet being a permutation of meit rapach, "288 have died"). The Sages teach us that the "Spirit of G-d" here referred to is in fact the soul of Mashiach (which permutes to shem chai, "the living name").

"Hovering" is symbolized in Torah "as an eagle arouses her nest and hovers over her young," as taught by the Maggid of Mezeritch. In order not to crush her young and their nest, the eagle hovers over her nest when feeding her young, "touching yet not touching." The eagle here is a metaphor for G-d in relation to His children Israel in particular and to the totality of His Creation in general. Were G-d to either fully reveal His ultimate Presence or withdraw His power of continuous re-creation, the world would instantaneously cease to exist.

Therefore, by "hovering" over created reality, G-d continues to sustain and nourish His Creation while simultaneously allowing each creature or, in the terminology of Kabbalah, each vessel, the ability to grow and develop "independently." The letter chet thus hints at the delicate balance between the revelation of G-d’s Presence to us (the vav of the chet) and the concealment of His creative power from His Creation (the zayin of the chet). 

This state of "hovering," "touching yet not touching," is the beginning of the phenomenon of "life to enliven." "Touching yet not touching" from Above thereafter reflects itself as "run and return" in the inner pulsation of every living creature. "And the living creatures [chayot] run and return like the appearance of lightning." Do not read chayot ("living creatures") but chayut, ("lifeforce").

The chatoteret, that sublime thin line that connects the two components or motion of the "life to enliven," itself points upward. It hints at "He who lives at the summit of the world," G-d’s "Essential Life." In truth, His Essence paradoxically fills and sustains all created reality while simultaneously "hovering" high above the level of the "hovering" lifeforce itself, unfathomable and beyond all human perception. 

The letter Chet is related to the gift of life (hayim) and to the sun (hama'), without which there is no life on earth. The influence of the sun constitutes three elevations: The first is light radiation, comprised of photons. The second is heat radiation – the heat that is distributed by the burning of the sun's corona. The third is related to the elevation of ‘electro-magnetic nourishment’, which comes to earth from the helio-sphere – the domain of the sun's influence. Thus, the sun is actually a universal window of opportunities for life on earth.

With regards to Chet being the eighth letter of the AlphaBet, this relates to infinity, to justice that is based on higher principles with no personal agenda, to a point of no return and to an uncompromised balance without fear. The only way to exit the infinite cycle of eight is through the middle point between the two circles, otherwise, Chet can be a fortified wall that cannot be penetrated.