Meditative Absorption
In the Revealing the Profound Secrets Sutra the Buddha tells World Voice Perceiver Bodhisattva:
There are three kinds of meditative absorption. The first is the meditative absorption that is without false discrimination but is quiescent, totally tranquil, and blameless so that defilements and many sufferings are cured and one can abide in happiness. The second is the meditative absorption that brings merit. The third is the meditative absorption that brings benefit to sentient beings.
T676, 16.705c20-705c22
The Awakening of Faith in the Mahayana briefly describes the two methods of Buddhist meditation, calming (S. Shamatha) and contemplation (vipashyana), leading to meditative absorption and ultimately wisdom.
How do you practice the gate of calming and contemplation? What is meant by calming? It refers to calming all the characteristics of the objective realm in accordance with the meaning of the shamatha method of contemplation. What is meant by contemplation? It is to discern the characteristics of the arising and ceasing of phenomena due to causes and conditions in accordance with the vipashyana method of contemplation. How should this be followed? Cultivate them both gradually and do not separate them so they will manifest together.
T1666, 9.582a12-582a16
This brief description is followed by a more lengthy explanation of the practice of calming and contemplation that goes beyond the scope of this brief introduction to the perfection of meditative absorption.
In the Bodhicharyavatara (Introduction to the Practice of Awakening) by the Indian Mahayana monk Shantidva (c. 685 - c. 763), the following is said about the importance of the perfection of meditative absorption:
1. Increasing one’s endeavor in this way, one should stabilize the mind in meditative concentration, since a person whose mind is distracted stands between the fangs of the defilements.
2. Distraction does not occur if body and mind are kept sequestered. Therefore, one should renounce the world and disregard distracting thoughts.
3. The world is not truly renounced because of attachment and the thirst for acquisitions and other rewards. Therefore, to renounce these, anyone with sense would reflect as follows:
4. Realizing that one well-attuned to insight through tranquility can destroy the defilements, one should firstly seek tranquility, and that by disregarding one’s delight in the world.
The Bodhicaryavatara 8.1-4 as translated by Kate Crosby and Andrew Skilton (adapted).
Further on in the same work:
38. Therefore I shall always follow the solitary life, which is delightful and free from strife, leading to the auspicious and calming all distractions.
39. Freed from all other concerns, my own mind in a state of single-pointed thought, I shall apply myself to taming and increasing the meditative concentration of my mind.
Ibid, 8.38-39
Shantideva goes on to describe in more detail the cultivation of contemplations on the decomposition of corpses to counteract sensual craving and the contemplation of exchanging oneself for others (imaginatively putting oneself in another shoes) to counteract dualistic egotism.
Among many examples, here is a story in which the bodhisattva who becomes Shakyamuni displayed the perfection of meditative absorption:
In a previous life, Shakyamuni Buddha practiced mediative absorption as the hermit Shankacharya. His compassion was said to embrace not only people but also all living beings. Because of this, he sat still for so long that a heron laid its egg on his head, and so as not to endanger it, he remained without moving, not only until the egg hatched but until the fledgling was old enough to fly away on its own.
The story of Shankacharya is briefly referred to in the Great Perfection of Wisdom Treatise.
A version of this story is also told The Three Jewels: A Study and Translation of Minamoto Tamenori's Sanboe.
Nichiren Shonin mentions the story of Shankacharya (J. Shoji) in his writings as an example of energy. (e.g. WNS7, p. 139)