The Lüelun Anle Jingdu yi 略論安楽浄土義 （T. 1957） of Tanluan 曇鸞 （476–542） consists of nine questions and answers. The ninth question and answer, located at the end of the work, raises a question on the meaning of shinian 十念. In the first half of this section, Tanluan introduces a parable to explain what shinian means. This parable is called the “Parable of crossing the river” （Jpn. toka no hiyu 渡河の譬喩） and, although various sūtras and treatises have been pointed to as the source of this parable, there has been no detailed examination, and the origin of the story has yet to be determined. In this paper, I compare the story with the “Parable of the four snakes in a box” （Jpn. ikkyō shida no hiyu 一篋四蛇の譬喩） found in the “Chapter of the Highly-virtuous King Bodhisattva （Dewang pusa pin 徳王菩薩品） of the Mahāparinirvāṇa-mahāsūtra （Dabanniepan jing 大般涅槃経）, and argue that this story is the source of the “Parable of crossing the river.” I further suggest that in the latter part of the answer to the ninth question, the influence of the “Parable of the four snakes in a box” can be seen.
