According to a blessing Milarepa uttered towards the end of his life, any person or animal who but hears the name Milarepa even once attracts an instant blessing and will not take rebirth in a lower state of existence during seven consecutive lifetimes. This was prophesied by Saints and Buddhas of the past even before his lifetime.
"Buddhas appear in the world in order to provoke inspiration in sentient beings, and manifest nirvana in order to provoke longing in sentient beings: in reality the buddhas have no appearance in the world and no nirvana either. Why? Buddha always abides in the pure realm of reality manifesting nirvana according to the minds of sentient beings." Avatamsaka Sutra