The Vitastā (later called the Jhelum) is a sacred river in Kashmir. The Vāmana Mahā Purāṇa tells its origin in Chapter 55. Bhagavān Vishṇu’s Sudarśana Cakra cut through the mountains to drain the Kashmir valley. This laid open the daitya Jalodbhava, who had been unbeatable while he stayed in the water. Bhagavān Śiva cut off his head. The drained waters, filled with the joint divine presence of Bhagavān Śiva and Bhagavān Vishṇu, became the river Vitastā. In the list of vibhūtis (divine presences) in Chapter 63, Vāmana names his presence in the Vitastā as Kumārila.

Origin: the draining of the Kashmir valley

The Kashmir valley was at first a vast lake. In it lived Jalodbhava, a daitya of the water. He had received a vara (boon) from Brahmā that made him unbeatable by ordinary attack. He troubled the lands around, and whenever he was attacked he went back into the deep water.

Bhagavān Vishṇu and Bhagavān Śiva made a plan together. Bhagavān Vishṇu used the Sudarśana Cakra to cut through the mountains that ring the valley, and so made a passage through which the waters could drain. As the lake emptied, Jalodbhava lost his refuge in the water step by step. At last he was laid open on the surface, and there Bhagavān Śiva cut off his head.

The waters ran out through the passage the cakra had made. They carried the divine power of the presence of both Bhagavān Śiva and Bhagavān Vishṇu, and they flowed out as the sacred river Vitastā. The valley, now drained, became a place where people could live. The Vāmana Mahā Purāṇa, Chapter 55, tells this.

Holiness of the Vitastā

The Sudarśana Cakra made the Vitastā, and it was formed at the place of this joint divine act, so it has special holiness. In Prahlāda’s tīrtha-yātrā (Chapter 53), he visits the Vitastā and worships Kumārila, the form of Bhagavān Vishṇu there. He bathes at the tīrtha (tīrtha-snāna) and his pāpa (sins) are destroyed.

In the list of vibhūtis, Vāmana says: “In Vitastā I am Kumārila.” The Vālakhilya ṛshis are said to worship Jyotirmaya Deveśvara at that tīrtha. The Vāmana Mahā Purāṇa, Chapters 55 and 63, tells this.

Sources

Vāmana Mahā Purāṇa, Chapter 53 (Prahlāda’s tīrtha-yātrā)
Vāmana Mahā Purāṇa, Chapter 55 (the origin of the Vitastā)
Vāmana Mahā Purāṇa, Chapter 63 (the list of vibhūtis)
Mahābhārata, Anuśāsana Parva, Chapter 146