One explanation is "talking without doing", that is, only talking and clarifying the theories of predecessors, and not creating them yourself. I think this explanation is far-fetched. Confucius said that learning without thinking is useless, and thinking without learning is dangerous. Thinking may lead to creation. Did Confucius just want to inherit the ideas of his predecessors and not want to have creative ideas? This obviously does not conform to Confucius' model. Moreover, in fact, Confucius teaches by example. Isn't the Confucianism he founded a kind of creation?
Another explanation is that Confucius' "words are not full of meaning" is actually explaining the teaching method of how to teach students knowledge, and it follows the original intention of the ancients to impart knowledge, rather than making it up at will (Tang). This view should be more correct.