मित्र and वरुण are invoked for protection against pervasive dangers and to ensure that malevolence does not reach the devotee [rv-7-50-1 ] rv • Book 7 . अग्नि is called upon to neutralize poisons lurking in natural corners [rv-7-50-2 ] rv • Book 7 . The universal deities are asked to eliminate poison from trees and waters [rv-7-50-3 ] rv • Book 7 , while divine rivers are entreated to flow unharmfully, providing nourishment without spreading disease [rv-7-50-4 ] rv • Book 7 .