The development of meditation in the Vedic era paralleled the ideas of "interiorization", where social, external yajna fire rituals ("Agnihotra") were replaced with meditative, internalized rituals ("Prana-agnihotra"). This interiorization of Vedic fire-ritual into yogic meditation ideas from Hinduism, that are mentioned in the Samhita and Aranyaka layers of the Vedas and more clearly in chapter 5 of the Chandogya Upanishad (~800 to 600 BCE), are also found in later Buddhist texts and esoteric variations such as the "Dighanikaya", "Mahavairocana-sutra" and the "Jyotirmnjari", wherein the Buddhist texts describe meditation as "inner forms of fire oblation/sacrifice". 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".