Another part of this book describes how the cosmic man Purusha was sacrificed by the gods to create the four castes.
One passage of this book describes a man with a thousand heads, a thousand eyes, a thousand feet, and claims that all creatures are one fourth of him. This book claims that there was once neither being nor non-being, and that only he in the highest heaven knows how the world was created, "but then, perhaps, he knows not," in a section that asks "What covered it?" "Where was it?" and "Was there cosmic (*) water?" That passage is called the "Nasadiya Sutka." Another part of this book describes how the cosmic man Purusha was sacrificed by the gods to create the four castes. The Aitareya Brahmana provides commentary on this book, which opens with an invocation of Agni. For 10 points, name this book of hymns, the oldest of the four Vedas.
One passage of this book describes a man with a thousand heads, a thousand eyes, a thousand feet, and claims that all creatures are one fourth of him.
Rig Veda [prompt on the Vedas]