The Shatapatha Brahmana is a major prose text describing Vedic rituals, symbolic meanings, and mythology. The story of Videgha (Videh) Mathava (Madhav) and his priest Gautama Rahugana details how they crossed the river Sadanira (identified with Gandak) and settled in the region of Videha (North Bihar), indicating the eastward movement of the Aryans from the region of Saraswati.