Bandha
Yogic texts expound the paramount role of bandha-s ("Locks" or "Bonds"), the practice of which involve pressure on particular parts of the body, and involve/assist in attaining the state of full concentration. Naṭarāja's posture expresses the key bandha-s. The position of the raised left foot suggests the Mūla-bandha, "the Basic(al) Bond", as it raises the apāna upwards. The high position of the diaphragm in the image of Naṭarāja, along with the band at that very position, is indicative of the Uḍyāna-bandha, "the Leap Bond", and the closeness of the chin and the neck is indicative of the Jālandhara-bandha, "Chin Lock".
"These three bandha–s (Locks) mastered," asserts Śaṅkara, "one transcends the fierce bandha ("bondage") of Time!". (Śaṅkara, Yogatārāvalī 5:
jālandharoḍyāṇana-mūla-bandhān
jalpanti kaṇṭhodara-pāyu-mūlān |
bandha-traye'smin paricīyamāne
bandhaḥ kuto dāruṇa-kāla-pāśāt ?||
जालन्धरोड्याणन-मूल-बन्धान्
जल्पन्ति कण्ठोदर-पायु-मूलान् ।
बन्ध-त्रयेऽस्मिन् परिचीयमाने
बन्धः कुतो दारुण-काल-पाशात् ?॥)
Śaṅkara's observation shows how it is through the practice of the trinity of yogic bandha(s), that the bandha ("bondage") of karmic processes is totally overcome.
The Relativity of Deva and Asura
This idea is powerfully expressed in the pressing of Apasmāra too, for it is by Naṭarāja's act that Apasmāra is freed of his āsura nature. The divine and diabolical natures are not settled once and for all in creation, but depend upon the way the freedom given is utilized: One may "fall" from an angelic character to a demoniacal one if he abuses the freedom/power given him; or equally, rise from an āsuric demeanour to a daivic one, if he presses his powers into the service of the noble ends. Towards what ends are our endeavours – is what determines our ascension and descension, our evolution into higher species (yoni-s), or baser ones; our progress into brighter beings or regress into lower creatures. Śaṅkara analyses this very well, and sets it forth succinctly in his commentary on an upaniṣad. See Śaṅkara on Bṛhadāraṇyakopaniṣad 1.3.1:
śāstrajanita-jñāna-karma-bhāvitāḥ dyotanād devā bhavanti, ta eva svābhāvika-pratyakṣānumāna-janita-dṛṣṭaprayojana-karmajñāna-bhāvitā asurāḥ |
शास्त्रजनित-ज्ञान-कर्म-भाविताः द्योतनाद् देवा भवन्ति, त एव स्वाभाविक-प्रत्यक्षानुमान-जनित-दृष्टप्रयोजन-कर्मज्ञान-भाविता असुराः ।