of Brahman, where subject-object duality had been dissolved. The early Buddhist practices adapted these old yogic methods, pairing it to mindfulness and attainment of insight. Kalupahana states that the Buddha "reverted to the meditational practices" he had learned from Alara Kalama and Uddaka Rāmaputta. In Hinduism, state Jones and Ryan, the term first appears in the Upanishads. Techniques of concentration or meditation are a Vedic tradition, states Frits Staal, because these ideas are found in the early Upanishads as dhyana or abhidhyana. In most of the later Hindu yoga traditions, which derive from Patanjali's Raja Yoga, dhyana is "a refined meditative practice", a "deeper concentration of the mind", which is taken up after preceding practices such as mastering pranayama (breath control) and dharana (mental focus). Discussion in Hindu texts Vedas and Upanishads The term dhyanam appears in Vedic literature, such as hymn 4.36.2 of the Rigveda and verse 10.11.1 of the Taittiriya Aranyaka. The term, in the sense of meditation, appears in the Upanishads. The Kaushitaki Upanishad uses it in the context of mind and meditation in verses 3.2 to 3.6, for example as follows: The term appears in the context of "contemplate, reflect, meditate" in verses of chapters 1.3, 2.22, 5.1, 7.6, 7.7 and 7.26 of the Chandogya Upanishad, chapters 3.5, 4.5 and 4.6 of the Brihadaranyaka Upanishad and verses 6.9 to 6.24 of the Maitri Upanishad. The word Dhyana refers to meditation in Chandogya Upanishad, while the Prashna Upanishad asserts that the meditation on AUM () leads to the world of Brahman (Ultimate Reality). Agnihotra 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. Beyond the early Upanishads