Dogen also said,
People who study the Way should not read the scriptures of the teaching-schools,
nor study non-Buddhist texts. If you wish to study, read the collections
of sayings [of the ancient Zen masters]. Put aside all other books
for the time being. These days, Zen monks are fond of reading literature,
composing poetry and writing dharma-discourses. This is wrong. Write
down what you think in your mind, even though you cannot compose poetry.
Write down the teachings of the dharma-gate, even though your style
is unpolished. People without bodhi-mind will not read it if it is
not polished. Such people would only play with words without grasping
the reality [behind them], even if the style were embellished and there
were excellent phrases in it.
I have been fond of studying literature since childhood, and even now I have a tendency to contemplate the beauty in the words of non-Buddhist texts. Sometimes I even refer to Monzen or other texts; still, I think it is meaningless and should be completely abandoned.