本願 (Skt purvapranidhana; Jpn hongan )
The vows made by a Buddha in the past while still engaged in bodhisattva practice. Of these, the forty-eight vows of Amida Buddha and the twelve vows of Medicine Master Buddha are especially well known. In the Pure Land school, "original vow" in the singular indicates the eighteenth vow of Amida Buddha—his promise to enable all people who invoke his name to be reborn in the Pure Land of Perfect Bliss in the west, excepting those who have committed the five cardinal sins and those who have slandered the correct teaching. The Sanskrit word purva of purvapranidhana means former or prior, and pranidhana means vow or prayer.