Śeṣa (शेष) the thousand-headed serpent, the emblem of eternity 1803 - 1804 British Library
Hindu Aesthetic wrote : Śeṣa (शेष) the thousand-headed serpent, the emblem of eternity. He is the son of Kadru and the King of the Nāgas or snakes inhabiting Pātāla. He is the serpent (Nāga) upon which Vishnu lies in the cosmic ocean.
His name means "that which remains", from the Sanskrit root śiṣ, because when the world is destroyed at the end of the kalpa, Śeṣa remains as he is.
In the Puranas, Śeṣanāga is said to hold all the planets of the Universe on his hoods and to constantly sing the glories of Vishnu from all his mouths. He is sometimes referred to as Ananta Śeṣa which translates as endless-Śeṣa or as Ādiśeṣa which means the first Śeṣa. It is said that when Ādiśeṣa uncoils, time moves forward and creation takes place. When he coils back, the universe ceases to exist.
The Bhāgavata purāna (5.25.2) says:
यस्येदं क्षितिमण्डलं भगवतोऽनन्तमूर्ते: सहस्रशिरस एकस्मिन्नेव शीर्षणि ध्रियमाणं सिद्धार्थ इव लक्ष्यते ॥
“Lord Anantadeva has thousands of hoods. Each sustains a global sphere that appears like a grain of mustard.”
Ananta instructs Lord Śiva how to destroy the cosmos, and thus He is sometimes called tāmasī, or “one who is in the mode of darkness.”
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