If you understand the first word of Zen
You will know the last word.
The last word or the first word,
Is not a word.

Wumen Huikai (1183 CE-1260 CE), Wumen Huikai was a Chinese Chán (Japanese: Zen) master during China‘s Song period. He is most famous for having compiled and commentated the 48-koan collection The Gateless Barrier.