  Taking into account all the available evidence, it seems likely that different collections of sayings attributed to Laozi expanded and gained currency during the fourth century B.C.E. They would have been derived from earlier, oral or written sources. During the third century B.C.E., the Laozi settled more or less into its final form. It was then quoted extensively in such works as the Hanfeizi and the “outer” and “miscellaneous” chapters of the Zhuangzi, and began to attract commentarial attention.