Acalā-bhūmi

acalā-bhūmi (T. mi g.yo ba མི་གཡོ་བ; C. budong di) is translated as the "immovable ground," "steadfast ground," "irreversible ground," etc. It is the eighth of the ten bodhisattva grounds (bhumis) according to the presentation in the Dasabhumika-sutra of the Sanskrit tradition.

In this ground, the bodhisattva masters the eighth paramita, the perfection of aspiration (praṇidhāna-pāramitā).

Peter Harvey states:

As a result of the seventh stage, at the eighth stage the Bodhisattva has reached a non-relapsing, irreversible (avinivartanya) level, such that he is now certain to attain Buddhahood. From this stage, his meditative insight imbues all his experience, and the many obscurations of the knowable (jñeyā-varaṇa) – preventing the omniscience of a Buddha – begin to be overcome. His knowledge enables him to appear anywhere in the universe at will, teaching beings while appearing just like them. He fully masters the transfer of karmic fruitfulness from his vast store, so that beings who pray to him receive it as a free spiritual uplift of grace.

Practical Ethics states:

Bodhisattvas on the eighth ground cannot be moved by the apprehension of signs or by the conception apprehending a self — both refer to true-grasping — or by the stains of the afflictive obscurations. Ordinary bodhisattvas and other ordinary beings who have not abandoned true-grasping are not able to understand the range of the physical, verbal, and mental activities of these bodhisattvas just as they are. That is, the way in which those bodhisattvas engage in virtuous activities of body, speech, and mind and the vastness of their virtuous activities is inconceivable for others.

The ripening result of the eighth ground is the ability to become a great Brahma king of the thousand worlds and thereby perform actions that are vastly beneficial for others. Hearer and solitary realizer arhats cannot surpass these bodhisattvas in analyzing, understanding, and explaining the meaning of the Dharma.

Sources

• Buswell, Robert E.; Lopez, Donald S. (2014), The Princeton Dictionary of Buddhism, Princeton University 
• Jampa Tegchok (2017), Thubten Chodron, ed., Practical Ethics and Profound Emptiness: A Commentary on Nargarjuna's Precious Garland, translated by Carlier, Steve, Wisdom Publications 
• Harvey, Peter (2013), An Introduction to Buddhism (Second ed.), Cambridge University Press