Kōgan Gengei (1748-1821) was a Zen priest of the Rinzai sect of Zen in the late Edo period. He was also known as Koshin’an. He studied under Hakuin Ekaku and his leading disciple Suiō Genro. In Tenmei 4 (1784), he resided at Kōgenji Temple in Tanba, where he greatly restored the temple’s dilapidated complex and devoted himself to the preaching of the masses.
The inscription is from a passage in the Lotus Sutra’s “Kanzenon Bosatsu Fumonbon (Kannon Sutra).”