赞玄
原文
视之不见，名曰夷；听之不闻，名曰希；搏之不得，名曰微。此三者不可致诘，故混而为一。其上不皦，其下不昧。绳绳不可名，复归于无物。是谓无状之状，无物之象，是谓惚恍。迎之不见其首，随之不见其后。执古之道，以御今之有。能知古始，是谓道纪。
王弼注
视之不见名曰夷，听之不闻名曰希，搏之不得名曰微。此三者，不可致诘，故混而为一。无状无象，无声无响，故能无所不通，无所不往，不得而知，更以我耳目体，不知为名，故不可致诘，混而为一也。其上不皦，其下不昧。绳绳不可名，复归于无物。是谓无状之状，无物之象，欲言无邪，而物由以成。欲言有邪，而不见其形，故曰，无状之状，无物之象也。是谓惚恍。不可得而定也。迎之不见其首，随之不见其后。执古之道，以御今之有。有，有其事。能知古始，是谓道纪。无形无名者，万物之宗也。虽今古不同，时移俗易，故莫不由乎此，以成其治者也。故可执古之道，以御今之有，上古虽远，其道存焉，故虽在，今可以知古始也。
英文 · James Legge
(The manifestation of the mystery) We look at it, and we do not see it, and we name it 'the Equable.' We listen to it, and we do not hear it, and we name it 'the Inaudible.' We try to grasp it, and do not get hold of it, and we name it 'the Subtle.' With these three qualities, it cannot be made the subject of description; and hence we blend them together and obtain The One. Its upper part is not bright, and its lower part is not obscure. Ceaseless in its action, it yet cannot be named, and then it again returns and becomes nothing. This is called the Form of the Formless, and the Semblance of the Invisible; this is called the Fleeting and Indeterminable. We meet it and do not see its Front; we follow it, and do not see its Back. When we can lay hold of the Dao of old to direct the things of the present day, and are able to know it as it was of old in the beginning, this is called (unwinding) the clue of Dao.