The Suvarṇaprabhāsa-sūtra (Ch: 金光明經; pinyin: jīn guāng míng jīng; JP: Konkōmyō Kyō), is a Buddhist text of the Mahayana branch of Buddhism. The title can be translated as the Golden Light Sutra or Sutra of the Sublime Golden Light. The sutra was originally written in India in Sanskrit and was translated several times into Chinese, by Dharmakṣema among others. The sutra is an important Mahayana sutra. It has been translated into Khotanese, Old Turkic, Tangut, Tibetan, Mongolian and Manchu. The name of the sutra derives from chapter 3 where the bodhisattva Ruchiraketu dreams of a great drum that radiates a sublime golden light, symbolizing the Dharma, or teachings of the Buddha.
Now almost forgotten in China, and no Buddhism in central Asia, it became one of the most important sutras in Japan because of its fundamental message, which teaches that the Four Guardian Gods (四天王) protect the ruler who governs his country in the proper manner. The sutra also expounds the vows of the Hindu goddesses Sarasvati, Lakshmi (Shri) and Drdha, the Earth Goddess, to protect any bhikkhu, or monk, who will uphold and teach the sutra.
Taken at face value one might take the main theme of the sutra literally, which is the importance for leaders to be good moral examples for the kingdom. In Chapter Twelve, the sutra speaks in verse form about the disasters that befall a kingdom when its ruler does not uphold justice, and the benefits of kings who lead and exemplary life. In the Chapter on the Guardian Kings, the Four Guardian Gings have a dialogue with the Buddha, explaining in vivid detail all the benefits a kingdom will have if its ruler enshrines the sutra and offers daily praise. The sutra contains some elements of early tantra, in that in chapter two, the sutra describes four Buddhas who dwell in the four cardinal directions. These same four comprise later Buddhist mandalas in the same positions, such as the Matrix Mandala.
Hence, historically the sutra won great esteem as a sutra for protecting the country, based on the text of the first chapter, and often was read publicly to ward off threats. Its first reading as a court ceremony was around 660 AD, when the Tang Dynasty of China and Silla of Korea had defeated Baekche of Korea and were threatening Japan.
In 741 Emperor Shōmu (聖武天皇) founded provincial monasteries (国分寺) and nunneries (国分尼寺) in each province. The official name of the monasteries was the Temple for Protection of the State by the Four Heavenly Kings Golden Light Sutra (金光明經四天王護国之寺). The 20 monks who lived there recited the Sovereign Kings Golden Light Sutra on a fixed schedule to protect the country. As Buddhism evolved in Japan, the practice gradually fell out of use, and is no longer continued today.
In some languages the sutra is preceded by a confession taught Zhang Judao (張居道) and a wife of an official, make an confession to the domestic animals they have killed and write the sutra and make a vow to these lives to early reincarnate into human realms. A Ming dynasty monk also collect some sutra effect.