This interiorization of fire rituals, where life is conceptualized as an unceasing sacrifice and emphasis is placed on meditation occurs in the classic Vedic world, in the early Upanishads and other texts such as the Shrauta Sutras and verse 2.18 of Vedic Vaikhanasa Smarta Sutra.
In the classical Vedic world, fire rituals are internalized, where life is conceptualized as an unceasing offering and meditation is stressed. This concept appears in early Upanishads and texts such as the Shrauta Sutras, with verse 2.18 of Vedic Vaikhanasa Smarta Sutra also conveying this meaning.