A Demonstration of the Six Spiritual Powers
195. Dharma Hall Discourse
Dogen drew a single horizontal line [the character for 'one'] with his whisk and said: Although this is so, ultimately, six times six is thirty-six.*
* 'Six times six is thirty-six' is simple, like 'one plus one equals two.' So this could be understood as saying that spiritual powers are simple, everyday matters. But 'six times six is thirty-six' also implies many powers beyond just six, indicating that there are not just thirty-six but innumerable spiritual powers. (Leighton & Okumura).
-- From Eihei Koroku, translated by Taigen Dan Leighton and Shohaku Okumura