The whole sentence is: Crows have the meaning of feeding back, and sheep know the kindness of kneeling to breastfeed. Human beings are not like vegetation, so how can they be ruthless? Know kindness in your heart and be grateful in action.
The general idea is: the little crow has the affection to feed the mother crow, the lamb has the gratitude behavior of kneeling down to receive breast milk, people are not flowers and trees, who can be ruthless and unrighteous? We must know gratitude in our hearts and put it into action. Children must also know how to be filial to their parents.
When the old crow cannot find food on its own, the young crow will regurgitate what it has eaten, that is, spit it out for the old crow to eat, to thank the old crow for its kindness. This is how animals grow. Later, the behavior of "supporting" parents in return. The lamb kneels when drinking milk, which is an act of gratitude.
Human beings are not grass and trees, which means that people have thoughts and feelings and are easily moved by external things, unlike grass and trees which are inanimate, unconscious and emotionless. Same as "people are not wood or stone".
Respecting and loving parents is what we often call "filial piety". The filial piety here is not simply “support”. Just having a son do things for his parents when things happen, and letting his parents eat first when there is food and wine is not complete filial piety. Real filial piety requires attentiveness and being kind to parents.
Explanation of related content
"Filial piety" as an ethical concept was formally proposed in the Western Zhou Dynasty. In the Western Zhou Dynasty, the meanings of filial piety were:
1. Respecting ancestors. The main way to perform filial piety is to offer sacrifices to ancestors in ancestral temples. The objects of filial piety are the dead, which has a certain religious form.
2. In the eyes of the people of the Zhou Dynasty, ancestors are the birthplace of our generation’s life. Therefore, worshiping ancestors is to continue the life of ancestors endlessly. In short, filial piety in the Western Zhou Dynasty was a kind of feudal religious ethics.