Widely used in Zen, but source unknown.
Shogen Yamakawa, abbot of Shogenji Temple and master of the Shogen Monastery It is an old saying, “If you sit for an inch, you will become a Buddha for an inch. The time it takes for a stick of incense to burn out is called “issun-no jikan. It is usually about five minutes or ten minutes. If you do this well, even if it is only for a short time, you will be able to say, “If you sit for an inch, you will become a Buddha for an inch. http://h-kishi.sakura.ne.jp/kokoro-857.htm
This page is auto-translated from /nishio/一寸座れば一寸の仏 using DeepL. If you looks something interesting but the auto-translated English is not good enough to understand it, feel free to let me know at @nishio_en. I’m very happy to spread my thought to non-Japanese readers.