Origin factually wrong edit

For many years this article had asserted an origin of the Sanzu River tradition in Buddhist enlightenment beliefs, in particular related to the mantra of the Heart Sutra. This was unreferenced, and is not at all supported by scholarly sources. Despite a vague formal similarity via the concept "river" no actual origin of the Sanzu tradition outside of Japan is likely. I have therefore removed this assertion until proper sources can be provided.  ‑‑ bs (2016‑Apr‑17)  All Japanese Buddhist traditions date the first Ohigan observation as in the early to middle part of Shotoku Taishi's career, which would be late 6th century or very early 7th century. Definitely not so late as ith century. Gregory Gibbs, Pasadena Buddhist Temple [BCA/Hongwanji-ha Jodo shinshu0