Chai (or Cha’i) means ‘living’ in Hebrew. In traditional Judaism, the sign, which consists of the Hebrew characters Chet Yod, represents charity, riches, and longevity. Because of its gematric (numerical) value of 18, Jews usually distribute charity in multiples of 18. The letter Chet is linked to the Tree of Life’s 18th path, which incorporates intelligence and influence, according to Kabbalistic sources.