The "Infinite Life Sutra" is the central Buddhist scripture for Jōdo-shū Buddhism, and the foundation of the belief in the Primal Vow of Amitābha. In addition to this, the "Amitāyurdhyāna Sūtra" and the "Amitabha Sutra" are important to the Jōdo-shū school. The writings of Hōnen, contained mostly in the "Senchaku-hongan-nembutsu-shū" (often abbreviated to "Senchakushū"), are another source for Jōdo-shū thought as is his last writing, the . Most of what is known about Honen and his thought is attributed through sayings collected in the following century, the "Senchakushū", and letters to his students and disciples.