Basic explanation
Metaphor things haven't been done yet.
derogatory sense
tidy
Sun Jinbiao's Popular Proverbs Personnel: Popular Compilation: The Book of Zhu Zi and Liu Zicheng: The sage opened eight characters, but people themselves don't understand. "According to today's statement, there is a proverb called' eight characters don't see two', which seems to be due to this language. People who have no end to everything are said to have never seen both sides of the eight characters. "