Here is the inimitable Master Sheng Yen at his best, illuminating the ancient texts of the Chinese Zen tradition to show how wonderfully practical they really are, even for us today.  The texts, written by two of the founders of the Ts’ao-tung sect of Chan Buddhism, are poems entitled
Inquiry into Matching Halves
and
Song of the Precious Mirror Samadhi
.  Both emphasize the Chan view that wisdom is not separate from vexation, and both speak of the levels of awareness through which one must pass on the way to realization. Both are also works of Buddhist philosophy that can serve as guides to spiritual practice for anyone.