The origin of "eight characters did not stay"

Book 3: Popular Compilation: The Book of Zhu Xi and Liu Zicheng: The sage opened eight characters, but people don't understand. "According to today's statement, there is a proverb called' eight characters don't see two', which seems to be because of this. People who have no end to everything are said to have never seen both sides of the eight characters. "

It means: Old Zhu said in his book "Harmony" that the sages have already written a word, that is, one left and one left (si), but ordinary people themselves have not understood it. According to this, the current proverb "You can't see two halves in eight characters" should be caused from here. Anything that hasn't been touched by the brain is called' eight characters haven't been seen yet'

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