云门一字关 (雲門一字關) yúnmén yīzì guān

yúnmén yīzì guān phrase one-word checkpoint; one-word barrier; yizi guan
Domain: Buddhism 佛教 , Subdomain: Chan
Notes: A method by Tang Chan master 雲門文偃 Yunmen Wenyan to answer questions with a single word (BL 'yizi guan'; FGDB '雲門一字關')