Confucius and his Favourite Disciple
Confucius and his followers were once stranded in the bordering area between the state of Chen and the state of Cai, and for seven days, what they had for their empty stomachs was only weeds from the woods. On the eighth day, Confucius was reclining on the ground to have a rest when Face-Back (Yan Hui) found some rice by beggaring. When Face-Back cooked the rice, Confucius happened to see Face-Back taking some cooked rice by Hand and eating it. When it was done, Face-Back offered the rice to Confucius with great respect. Confucius pretended to be unaware the fact that the rice had been touched by Face-Back’s hand and therefore unsuitable for ritual occasions, and said, "I have seen my deceased king in my dream, please offer the rice as sacrifices to my deceased king."
"No," Face-Back said. "During the cooking, ash fell into the pan. Since it is ominous to throw away food messed with ash, I grabbed it with my hand and ate it."
After a deep sigh, Confucius says, "Seen is true, but seen is not necessarily true. To rely on our hearts to judge, and our judgment is not always reliable. Disciples, please take note: It is not easy to know a man well." (From: Lu's Spring and Autumn Annals)