What is "purushamedha"

Purushamedha (or, 'Naramedha', literally translated, " human sacrifice") is a Śrauta ritual, closely related to the Ashvamedha. The Vajasaneyi Samhita-Sataphana Brahmana-Katyayana Srauta Sutra sequence of White Yajur Veda texts contains the most details. Since there is no inscriptural or other record of Purushamedha ever being performed, some scholars suggest it was invented simply to round out sacrificial possibilities. In Shatapatha Brahmana 13.6.2, an ethereal voice intervenes to halt the proceedings.