According to Mahayana Buddhist sutra, Amitabha was a king who became monk and named as Dharmakara. He took great vows for saving the sentient beings-'If upon the attainment of Buddhahood all sentient beings in the ten quarters who aspire in sincerity and faith to be reborn in my land, recite my name up to ten times and fail to be born there, then may I not attain the Perfect Enlightenment’