Rivers, such as the Sapta Sindhavah ("seven rivers" Sanskrit: सप्त सिन्धव), play a prominent part in the hymns of the Rig Veda, and consequently in early Hindu religion. It may have been derived from an older Proto-Indo-Iranian hydronym, as a cognate name, hapta həndu, exists in the Avestan language.
A recurring theme in the Yajurveda is that of Indra slaying Vritra (literally "the obstacle"), liberating the rivers; in a variant of the myth, Indra smashes the Vala cave, releasing the cows that were within. Though the two myths are separate, rivers and cows are often poetically correlated in the Rigveda, for example in 3.33, a notable hymn describes the crossing of two swollen rivers by the chariots and wagons of the Bharata tribe:
The Seven Rivers are a group of seven chief rivers of uncertain or fluctuating identification (the number seven is of greater importance than the exact members of the group)- compare the Saptarishi of the Avesta (and also the later seven seas and the seven climes) . The Avesta's hapta həndu are preemptively equated with the Vedic Sapta Sindhavaḥ or vis-a-vis: in Vendidad 1.18 these are described to be the fifteenth of the sixteen lands created by Mazda. Note: The term Sapta Sindhava, commonly used in Hindi and other Indian languages, is the nominative plural in Sanskrit (dropping the final visarga in conformity with the convention when expressing Sanskrit words in modern languages). Sapta Sindhu, often seen in English, is in the singular, and is therefore ungrammatical.