Maṇikarṇikā is the most sacred tīrtha in the Avimukta kshetra of Kāśī. It is the best of all the places that give moksha (liberation). Every act of dharma done here gives lasting liberation, and Bhagavān Śiva as Dhūrjaṭi is always present here.

Its story begins before the universe was made. Bhagavān Vishṇu dug the Cakrapushkariṇī pond with his discus and did fifty thousand years of tapas on its bank. When Bhagavān Śiva came to give him varas (boons), his gem earring (maṇikarṇikā) fell into the water. That is how the tīrtha got its eternal name.

Origin of the name

The Kāśī Khaṇḍa tells this as the teaching of Bhagavān Śiva to Pārvatī, passed on through Skanda to Agastya. Before the universe came to be, Bhagavān Śiva made the Avimukta kshetra (Ānandavana) as his own pleasure-ground. He then made Bhagavān Vishṇu from his left side and gave him the work of creating and sustaining the world.

Bhagavān Vishṇu dug a lovely lotus pond, the Cakrapushkariṇī, with his discus (cakra). He filled it with drops of sweat born of his own tapas. Then he did fifty thousand years of tapas on its bank without moving.

When Bhagavān Śiva came to give him varas, he shook his head in approval of Bhagavān Vishṇu’s great tapas. His gem earring (maṇikarṇikā) fell from his ear into the pond. Bhagavān Śiva said that from then on the tīrtha would be called Maṇikarṇikā. Bhagavān Vishṇu added a vara: that this tīrtha should be the greatest of all places that give moksha, and that it should also bear the name “Kāśī”, because of its brilliance beyond words (kāś means to shine). (Kāśī Khaṇḍa, Chapter 26)

Its greatness

Maṇikarṇikā is the greatest śmaśāna (cremation ground) and yoga-pīṭha of Kāśī. Several Purāṇas name these powers of the tīrtha:

Bathing at Maṇikarṇikā gives the puṇya (merit) of the Daśāśvamedha yajña (Nārada Purāṇa).
Dīpadāna (offering a lamp) here lights the senses with the light of jñāna (knowledge) (Nārada Purāṇa).
Dhūpa-dāna (offering incense) wins the seat of Rudra (Nārada Purāṇa).
Setting free a four-year-old bull at Maṇikarṇikā gives moksha (Nārada Purāṇa).
Every act of dharma done here gives lasting liberation. This includes snāna (bathing), japa, homa, dāna, study of the Vedas, tarpaṇa and setting up a Liṅga (Kāśī Khaṇḍa).
Bhagavān Śiva as Dhūrjaṭi is always present at Maṇikarṇikā. It is his permanent seat within the kshetra (Nārada Purāṇa, Kāśī Khaṇḍa).
When the Devas came to Kāśī, they first bathed at Maṇikarṇikā in their garments, before any other act in the holy city (Kāśī Khaṇḍa, Chapter 3).

The first act of the pilgrimage

The Devas came to Kāśī to ask Agastya for help with the trouble caused by the Vindhya mountain. Their very first act was to bathe at Maṇikarṇikā with their garments on. They did this before they offered tarpaṇa to the pitṛs (ancestors), before they honoured the people who lived there, and before they visited Viśvanātha. (Kāśī Khaṇḍa, Chapter 3)

Maṇikarṇikā as the Mahāśmaśāna

The Kāśī Khaṇḍa calls the whole Kāśī kshetra the Mahāśmaśāna, the Great Cremation Ground. Maṇikarṇikā is the heart of it. Here two forms of Bhagavān Śiva live side by side: his śmaśāna-svarūpa (his cremation-ground form) and his ānanda-svarūpa (his form of bliss). Death here is not an end. Bhagavān Śiva whispers the tāraka-brahma into the ear of the dying person, and the ātmā becomes Brahman itself.

Cakrapushkariṇī

The Cakrapushkariṇī is the holy water of Maṇikarṇikā. It is the pond that Bhagavān Vishṇu dug with his discus. It is filled with the sweat of his fifty thousand years of tapas, which makes it the most powerful of all holy waters. Its name tells of two things: it was dug by the cakra (discus), and it looks like a lotus pool.

Maṇikarṇikā in the Pañcatīrthī

Chapter 61 of the Kāśī Khaṇḍa (Uttarārdha) names Maṇikarṇikā as one of the Pañcatīrthī, the five greatest tīrthas of Kāśī. A round of all five destroys all the karma gathered in all births. The five are:

The confluence of the Asī and the Gaṅgā (in the south)
Daśāśvamedha Ghāṭa
Pādodaka (at the confluence of the Varaṇā and the Gaṅgā, near Ādikeśava)
Pañcanada
Maṇikarṇikā

Chapter 83 lists the same five as the most exalted tīrthas in the kshetra. It says that a round of all five is the highest prāyaścitta (atonement).

The declaration of Bhagavān Śiva: three things are essential

In Chapter 99 of the Kāśī Khaṇḍa (Uttarārdha), the last chapter, Bhagavān Śiva spoke from the Śṛṅgāra Maṇḍapa of Kāśī after his great coronation. He raised his right hand and said before all the Devas, ṛshis and Gaṇas:

“Lifting up my hand, I assert again and again that in this world having the three Vedas, only three things are essential: Viśveśa Liṅga, Maṇikarṇikā water, and the city of Kāśī. This is the truth, threefold truth.”

He also said: “There is no Liṅga equal to that of Viśvanātha. There is no Tīrtha other than Maṇikarṇikā. There is no tapas grove anywhere else on a par with my Ānandavana.”

In these words of Bhagavān Śiva, Maṇikarṇikā is the one tīrtha that has no equal. The Kāśī Khaṇḍa also says that Maṇikarṇikā stretches five hundred hands from north to south within the Gaṅgā, in the middle of the most sacred part of Kāśī.

Sources

Skanda Mahā Purāṇa, Kāśī Khaṇḍa, Chapters 3, 26, 61, 83, 99.
Nārada Mahā Purāṇa, Uttarardha, Chapters 48–50.
Kūrma Mahā Purāṇa, Poorvardha, Chapter 34.