འཕགས་པ་བྱང་ཆབ་སམས་དཔའ་བྱམས་པ་དགའ་ལྡན་གནམ་ད་སྐྱ་བ་བླངས་པའ་མད notes.55

notes.55

55. Here, we have opted for faithfulness to the Tibetan translation, although it seems to have overlooked an intertextual reference in the Chinese sūtra. The latter actually makes two separate claims: first, that after fifty-six trillion years have passed, Maitreya will leave Tuṣita to take birth in Jambudvīpa; and second, that this fact was taught in a text entitled the Sūtra on the Descent of Maitreya. That text (its title in Chinese is 彌勒下生經) may refer to the earliest of the Maitreya sūtras, translated in 303 ce by Dharmarakṣa (Taishō 453), which goes by this name. The similarly-titled Sūtra on the Descent and Enlightenment of Maitreya (彌勒下生成佛經) was translated by Kumārajīva (Taishō 454). In sum, either the Tibetan translators were not familiar with this Chinese sūtra or were working from a source manuscript with another reading.