The Ullambana Sutra (佛說報恩奉盆經) is a Mahayana sutra which consists in a brief discourse given by the Gautama Buddha principally to the monk Maudgalyāyana (Mokuren in Japanese) on the practice of filial piety. In the Ullambana Sutra, the Buddha instructs his disciple Mahāmaudgalyāyana on how to obtain liberation for his mother, who had been reborn into a lower realm, by making food offerings to the sangha on the fifteenth day of the seventh month. This practice is the basis of the Obon ceremony in honor of one's ancestors which is still observed widely in Japan.