Tian-xing 天行 is one of the five practices of bodhisattvas described in the section of the Mahāparinirvāṇa-mahāsūtra （hereafter MPNMS） translated by Dharmakṣema that is unique to this version. In this sūtra, however, it is said only that the content of this practice is described in the Zahua 雑華, which may be a scripture or something but doesn’t exist now. Basing myself on fragmentary materials, I try to reconstruct this Tian-xing. First, in MPNMS, Tian as a god may lead readers to recall the image of longevity. Buddha is called a god who surpasses all other gods （Tian-zhong-tian 天中天） because he has an immeasurable lifespan and gives it to all sentient beings. Buddha preaches that Bodhisattvas should give up their lives as he did. This Bodhisattva offering is seen also in the Zahua. From these points, I assume that Tian-xing is the Bodhisattva practice of offering one’s life. Moreover, the merciful heart supporting this offering is declared in detail in MPNMS. There is no description of Tian-xing, but its ideological groundwork can be found in MPNMS.
