求仙不识真铅汞，闲读丹书千万篇。
Those who implore immortals won’t realize true lead and mercury.
Calmly read the alchemical books over and over again.

内里明来是至真，外边入者即非亲。
When you know their inner principle then arrive at what is real.
Anything coming from outside (the body) is not the real ancestor.
– Chen xiyi, pointing out the mystery essay.