The Great Way is not difficult
for those who have no preferences.
Obey the nature of things,
and you will walk freely and undisturbed.
When thought is in bondage
the truth is hidden,
for everything is murky and unclear,
and the burdensome practice of judging
brings annoyance and weariness.
To come directly into harmony
with this reality just simply say
when doubt arises, “not two.”
In this “not two” nothing is separate,
nothing is excluded.
Faith Mind Poem
from Zen Mountain Monastery Liturgy Manual
108zenbooks 
Sengcan’s poem reminds me of the debt Zen owes to the Taoist tradition, with its emphasis on harmony and alignment – qualities rare enough in daily life.
If we seek harmony and alignment, then we must give up our preferences and exclude nothing.
Hard training.
There are so many verses of the TTC folded into this poem. Thank you for identifying it as Sengcan.