ANCESTORS, a proverbial phrase, Seven Quan and Seven Zhu, indicate Our Uncountablee Ancestors from time immemorial. Cao, Tang To, Khao
CUU HUYEN: In a Han sense, Cuu Huyen means Nine Generations, consisting of: Cao, Tang, To, Khao, Ky, Tu, Ton, Tang and Huyen. That is, above us there are four levels, So (Great Great Grand Father), Co (Great Grand Father), Noi (Grand Father) and Cha (Father). Below are the four levels: Child, Grand Child, Great Grand Child, Great Great Grand Child. Formerly, The Ha Vo dynasty in China cast nine bronze caudrons to worship the ancestors of their clan. The Nguyen dynasty in Vietnam also created nine caudrons which were installed at the Royal Temple (Thai Mieu) for the same purpose. It is noteworthy that worshipping is aimed at the senior four levels, which have passed and salvage and common responsibility apply to the junior four levels.
SEVEN TO: In Buddhism, Seven To mean Ancestors of Seven Generations, originating from the phrase "Thất Thế Phụ Mẫh", Seven Generation Parents. That is, each time a body is born, it always has its ancestors and seven such generations are called "Ancestors of Seven Generations". According to Indian customs, number 7 is symbolic of 'Plural one' (Uncountable). It is because, from time immemorial, a human has passed and is reborn for an innumerable times, therefore Seven To mean the parents and grand parents from so many lifes. Lord Master said: "
"The day you acquire six supernatural powers,
You may salvage the parents and seven generation ancestors."
(Poem to Ô. Cò Tàu Hảo)
In light of the two above analyses, "Cuu Huyen That To" is a proverbial phrase which combine two words Cuu Huyen (Ruism) and That To (Buddhism). Initially they were used to wish each other (Wish for Cuu Huyen, That To, maternal and paternal sides respectively), subsequently it became a habit and served as a saying common to the grand parents and parents from myriad lives.