The form of Narayana is linked with the concept of sacrifice in the earliest known references to him. In Vedic sources such as the Purusha sukta, Narayana is given as the name of the self-offering of the great cosmic sacrifice of the Rig Veda. Narayana is not mentioned in Rig Veda itself, but came to be regarded as the seer who authored the hymn. It is possible that the sage who composed the Purusha Sukta hymn has been assimilated to the Purusha whose praise he had sung, and he himself became the object of worship. Mentions of a divine sage named Narayana, along with counterpart Nara, appears in many Puranic texts. Purusha is also identified with Vishnu in the Rig Veda and interpreted accordingly by many traditions of Vaishnavism. In the Bhagavata he is recognized as the Lord whose being is sacrifice, Yajna Purusha Some believe that thus this verse of the Rig Veda is a foundation of Vaishnava tradition. In the Gopala Tapani Upanishad the Rig Veda verse(1.22.20) was addressed paraphrasing the original of the Vedic hymn in accordance with the beliefs of the Gaudiya Vaishnava: It outlines a specific view held by the Gaudiya Vaishnava and Vallabha Sampradaya, that the conclusion of Vishnu worship is meditation on gopa-rupah or specific form of Krishna.