Nichiren Daishonin states in “Letter to Ni’ike”
It is said that the Kankucho bird in the Snow Mountains suffers from the cold at night and cries out it will build a nest after dawn. But when the sun rises, it is lulled to sleep in the warmth of the morning sun, and again, does not build its nest. For its whole life, it keeps screeching in vain. The same applies to humans. Upon falling into hell, we suffer in anguish in raging fires, yearning to be reborn as a human so that we can make offerings to the three treasures before everything else and attain enlightenment in the future. However, when we happen to be reborn as a human, the wind of desire for fame and fortune blows fiercely, easily extinguishing our light of determination for Buddhist practice.
宗祖日莲大 圣 人于《新池御书》曰: