佛祖統紀 31.15

31.15

The commentary says: The people of the northern continent have a fixed lifespan of one thousand years, and therefore do not weep or mourn over death. Buddhas do not appear there, and therefore they do not hear the Buddha Dharma. This is why it is one of the eight difficulties. Ancient writers remarked that the *Liezi*'s account of the Yellow Emperor dreaming of wandering to the country of the Huaxu clan refers to the northern continent; it is not known whether this is correct. Because in the southern continent there is the Buddha Dharma to be learned, those of Mahāyāna capacity are mostly born into it. Because their lifespan is brief and hurried and they are oppressed by various sufferings, out of fear and dread they give rise to the mind [for bodhi] and diligently cultivate the practice of the Way. This is why it is the most superior among the four continents.