According to the Larger Sukhavati-vyuha Sutra, the monk Dharmakara studied the qualities of countless existing Buddha-lands before vowing to construct one land that combined every excellence and excluded every deficiency he had observed. He then practised for aeons to fulfil forty-eight specific vows, the eighteenth of which is central to the entire Pure Land tradition: that any being who sincerely calls upon him with faith, even as few as ten times, will be reborn in his land — with the sole exception of those who have committed the five gravest transgressions or rejected the true Dharma.
Having fulfilled every vow, Dharmakara became the Buddha Amitabha and Sukhavati came into existence exactly as promised: a realm free of suffering, lower rebirths, and the ordinary obstacles to practice, where the environment itself — jewelled trees, birdsong, gentle breezes — is said to naturally teach the Dharma to anyone reborn there, making final enlightenment, in Pure Land teaching, no longer a matter of chance.