Foot red: pure gold, pure gold. There is no pure gold. Metaphor: Nothing is perfect. Perfect person: a perfect person, a person without any shortcomings. It is also a metaphor that you can't ask a person to be free from faults and mistakes.
From Dai Song Fugu's "Xing Xing": "Gold has no color, but white jade has slight defects. I am not prepared for help, I wish the old gentleman a family. "
Every kind of wine is reduced. Every wine has a precipitate. )[