The Lotus Sutra speaks of “someone finding a ship in which to cross the water.” This “ship” might be described as follows: As a shipbuilder of infinitely profound wisdom, the World-Honored One of Great Enlightenment, the lord of teachings, gathered the lumber of the four flavors and eight teachings, planed it by honestly discarding the provisional teachings, cut and assembled the planks, forming a perfect unity of both right and wrong, and completed the craft by driving home the spikes of the one true teaching that is comparable to the flavor of ghee. Thus he launched the ship upon the sea of the sufferings of birth and death. Unfurling its sails of the three thousand realms on the mast of the one true teaching of the Middle Way, driven by the fair wind of “the true aspect of all phenomena,” the vessel surges ahead, carrying aboard all people who can “gain entrance through faith alone.” The Thus Come One Shakyamuni is at the helm, the Thus Come One Many Treasures takes up the mooring rope, and the four bodhisattvas led by Superior Practices row quickly, matching one another as perfectly as a box and its lid. This is the ship in “a ship in which to cross the water.” Those who are able to board it are the disciples and lay supporters of Nichiren. Believe this wholeheartedly.WND I: 3, p. 33
Nichiren Daishonin wrote this letter at Kamakura in the first year of Kōchō (1261), about two weeks before he was exiled to Itō in Izu. Virtually nothing is known about the recipient, Shiiji Shirō, other than that he lived in the province of Suruga and was acquainted with two of the Daishonin’s leading disciples, Shijō Kingo and Toki Jōnin.
The title of this letter is drawn from a passage in the “Medicine King” chapter of the Lotus Sutra that speaks of “a ship in which to cross the water.” In this letter, the Daishonin teaches that the daimoku of the Lotus Sutra is the “ship” that can unfailingly transport one across the sea of life’s inevitable sufferings to the distant shore of enlightenment.