Also, the life-span of this Buddha and his people is an infinite number of
immeasurable eons, and so he is called Amitabha. Amitabha Buddha attained
enlightenment ten eons ago.
In this world, to be reborn as a human being is an unbelievably rare opportunity. Such a birth is as rare as a turtle rising from the depths of a vast sea to break through the surface into the center of a solitary wreath of flowers floating on the water. As incredibly rare as this is, far rarer is it to be reborn as a human at a time when a Buddha is teaching the Dharma. We can see this in our world Endurance.
Almost 3000 years ago, Sakyamuni Buddha taught in our world for forty-nine years. He said that the teachings would remain here for 12,000 years. This stretch of time would comprise three ages: the Dharma Perfect Age, the Dharma Semblance Age, and the Dharma-Ending Age.
We have already entered the last age, the Dharma- Ending Age, which will continue for 9000 more years. Sakyamuni Buddha said that when this age comes to a close, the teachings will be lost to us for 5,670 million years at which time Maitreya Bodhisattva will come to this world. He will come to this buddha-land, to become a Buddha and teach us the Dharma.
Conversely, in the Pure Land, Amitabha Buddha has been teaching for ten kalpas, or eons, and is still teaching! What’s more, he will continue to teach for an incredibly long time because his lifetime “is an infinite number of immeasurable eons.”
Infinity and asamkhyeya, signify particular numbers in the ancient numbering system of India, just like one million is a specific number today. The Avatamsaka Sutra lists 144 such numerical units, with asamkhyeya and infinity among the ten largest. When used in the sutra, infinite means a number so inconceivably large that we are incapable of calculating it. Nonetheless, it does represent a given span of time. So even a lifespan of “an infinite number of immeasurable eons” will eventually end.
When Amitabha’s lifespan ends, and he passes into final nirvana, Avalokitesvara will become the next Buddha in the Pure Land. Then, after Avalokitesvara enters final nirvana, Mahasthamaprapta will become the next Buddha. From this, we can see yet another of the inconceivable advantages of being born in the Pure Land. Not only is the environment ideal, but we already know two of the future Buddhas who will continue teaching there when their predecessors enter final nirvana. Knowing who the next two Buddhas in the Pure Land will be assures us of the amazing continuity of the teachings.
— Chapter 26, "Pure Mind, Compassionate Heart: Lessons from the Amitabha Sutra", Venerable Wuling