Cha’i in Hebrew means living or alive. The image represents the word as written in Hebrew letters (right to left): Cheth Yod. In Judaism, the word is used an emblem of charity, longevity, and good fortune. Gematrically, Chai enumerates to eighteen; therefore, the number is associated with the life-force and the immanent presence of God. It is entirely due to this symbolism that Jewish charitable giving is traditionally parceled out in multiples of 18. In Kabbalah, the letter Chet corresponds to the eighteenth ‘path’ on the Tree of Life, between Binah and Geburah.
In esoteric (so-called “western”) kabbalah, this path is associated with the 7th card of the tarot, the Chariot, which is itself associated with generative forces, and the Merkabah- the “throne chariot” or divine vehicle of God as described in the visions of the Old Testament prophet Ezekiel.
Chariot Tarot card, from Aleister Crowley’s Thoth deck