Shin Buddhist Service Book P.101
The Smaller Sukhavativyuha-Sutra was a discourse given to Sariputra and 1250 disciples in the Garden of Jetavana in the country of Sravasti. In this Sutra the Buddha describes the beauty of the Pure Land, the Virtues of the Amida as being a Buddha of Infinite Light and Infinite Life. The Buddha taught that the only way to attain rebirth in this Pure Land is by repeating the Holy Name, Namo Amida Butsu, with firm Faith. The Sutra further states that the innumerable Buddhas of the Universe praised and vouched for the Truth of the Nembutsu.
from Shin Buddhist Service Book