This sentence comes from Sima Qian's Historical Records: A Family Leaving Hou in the Western Han Dynasty. The whole paragraph reads as follows: "Father had enough and left with a smile. Liang Shu was frightened and looked at it with his eyes. My father went to school and came back and said,' A good boy can teach. "
Children can't teach. Describe the child as stupid and impossible to build.
Analysis: I wish my son would not teach, which is often matched with "rotten wood cannot be carved". Wishing the child here refers to the child, which means that the child's mind is not mature enough to draw inferences from others, and it is useless to reason with him.