Is the word “ineffable” a paradox?
Literally: non – stand – sentence – letter
Alternately: The Buddhist observation that satori (“understanding,” specifically insight into the true nature of reality) is not something that can be written down or put into words. By extension, anything difficult or impossible to express. Ineffability; indescribability.
Notes: This phrase seems to be particularly associated with Zen Buddhism, and is attributed to a 13th-century CE koan collection, The Gateless Barrier (Japanese 『無門関』 = Mumonkan)
Reading 不立 as furitsu or 文字 as moji is considered an error.
There are a number of synonyms and related terms, including 以心伝心 and 拈華微笑.