Three hymns and several verses praise Sarasvati as a river in flood from the mountains to the sea. She bursts the hill ridges like someone digging lotus stems, is an iron fort, has seven sisters, and is best of mothers, rivers and goddesses. She gave a son to Vadhryashva and plenty to Nahusha, has the Maruts for friends, wakes good thoughts, and is asked never to send her people away to other fields.
Balarama, refusing to fight, makes a pilgrimage along the Sarasvati. At Vinashana the river is invisible. Sages tell him she has seven forms because she appears wherever she is called: at Pushkar for Brahma as Suprabha, at Naimisha, at Gaya, in Kosala for Auddalaka, at Kurukshetra for Kuru when Vasishtha calls her. When the banks were too crowded for the sages she turned her course to make room. Balarama ends by singing that there is no happiness like living beside her.
What is different here:
The river now disappears and reappears; she is summoned by thought; her greatness is as a chain of bathing places, not as a flood.
The ritual text prescribes a moving sacrifice up the Sarasvati. It begins where she is lost, at Vinashana, and goes against the stream to Plaksha Prasravana, forty days on horseback, which is also said to be the distance to heaven. The gods once propped the sun with her; she gave way, and so she is full of bends.
What is different here:
The earliest text read that knows the vanishing place; gives the river's bends a cause; no personal goddess speaks.
Sources: Hymns of the Rigveda, tr. R. T. H. Griffith (1896), hymns read for the Vedic layer; The Mahabharata, tr. K. M. Ganguli (1883-96), sections read for the Vedic layer; Pancavimsa-Brahmana: the Brahmana of Twenty Five Chapters, tr. W. Caland (Bibliotheca Indica, 1931)