No, it's a quote. If a person cobbles together other books at random, in another way, it is of course plagiarism. If he can prove that the similarity is just a coincidence, he will take out his own manuscript. The original text shows that the work was created through one's own mental labor and intelligence, which can be considered as not plagiarism.

Legally speaking, plagiarism is a copy of the original without modification or basically without modification, which belongs to copyright infringement. But sometimes it is difficult to define whether it constitutes plagiarism. For example, it is controversial whether imitating the plot of a story is plagiarism. Some people think that the story belongs to the category of thought, and "ideological plagiarism" is not a criminal act, because the law only protects the expression of thought, not the thought itself.