The Gateless Barriers Mumokan

Sanbao "three treasures" first occurs in Tao Te Ching chapter 67,
which Lin Yutang (1948:292) says contains Laozi's "most beautiful teachings":

天下皆謂我道大，似不肖。夫唯大，故似不肖。若肖久矣。其細也夫！我有三寶，持而保之。一曰慈，二曰儉，三曰不敢為天下先。慈故能勇；儉故能廣；不敢為天下先，故能成器長。今舍慈且勇；舍儉且廣；舍後且先；死矣！夫慈以戰則勝，以守則固。天將救之，以慈衛之。 ^[1]

The Wumen Guan has an appendix titled "Zen Caveats" (禪箴) with one-line aphorisms dealing with Zen practice The word zhēn (箴) means "caveat", "warning", or "admonition", but it also has the meaning of "needle" or "probe" (as in acupuncture needles) and is sometimes translated as "Zen Needles". As with the main koans, each caveat challenges the Zen student's attachment to dualistic concepts, here those especially related to Zen practice.

Following the rules and protecting the regulations is binding oneself without rope.

Moving freely vertically and horizontally without obstruction is the way of outsiders and the nightmare army.

To preserve the heart mind and to purify it by letting impurities settle to the bottom in quiescence is the perverted Zen of silent illumination.

Neglecting the written records with unrestrained ideas is falling into a deep pit.

To be awake and not ignorant is to wear chains and shoulder a cangue.

Thinking good and thinking evil are the halls of heaven and hell.

A view of Buddha and a view of Dharma are the two enclosing mountains of iron.

A person who perceives thoughts as they immediately arise is fiddling with spectral consciousness.

However, being on a high plateau practicing samadhi is the stratagem of living in the house of ghosts.

To advance results in ignoring truth; to retreat results in contradicting the lineage.

Neither to advance nor to retreat is being a breathing corpse.

Just say, how will you walk?

You must work hard to live in the present and, to finish, all the more. I do not advise the unfortunate excess of continual suffering.