Mandala 4, credited to the Vamadeva family, follows the standard shape of the family books, 58 hymns weighted heavily toward Agni and Indra, with the Ashvins, the divine twin horsemen who rescue the shipwrecked and the sick, receiving unusually sustained attention as well. Vamadeva's hymns to Indra dwell repeatedly on the god's defining act, the slaying of the serpent Vritra who had imprisoned the world's waters, retold across the Rig Veda in dozens of variations but treated here with particular narrative energy, alongside praise for Indra's strength, his thunderbolt weapon, and his role as the paradigmatic warrior-god whose victories the human patrons of the sacrifice hoped to share by association.
The book also contains one of the Rig Veda's notable riddle hymns, dense, deliberately cryptic verses whose imagery scholars still debate rather than treat as settled, a genre found scattered through several family books and generally read as reflecting an esoteric, initiatory strand within the wider sacrificial tradition. Vamadeva himself appears in later tradition as a figure of unusually early and precocious wisdom, with some Vedic passages, outside this mandala, associated with a claim of pre-natal or infant insight, a detail later commentarial literature developed at length.