Maitrayaniya Upanishad 2.5.5

2.5.5

ityarthaḥ | evaṃvidhakriyāvattvamevāsya lakṣaṇamuktaṃ veditavyam | evamuttaratrāpi yojanā | atha yo'yaṃ vāyuviśeṣo'vāṅnābheradhaḥ pāyuparyantaṃ saṅkrāmati sañcaratyeṣa vāva so'pāna iti pūrvavadyojanā | uddeśakramaṃ parityajya madhye vyānaṃ lakṣayati tasya prāṇāpānasandhitvena tayorantarā niyatattvāt | tathā ca śrutyantaraṃ' atha yaḥ prāṇāpānayoḥ sandhiḥ sa vyānaḥ' iti | caramato'syoddeśastu sarvaśarīraceṣṭādihetutvena sarvaprāṇavyāpakatvāditi draṣṭavyam | atha yena vāyuviśeṣeṇa etā etau prāṇāpānau anugṛhṇītā anugṛhṇautau ityevaṃ vartamāna eṣa vāva sa vyānasañjñaḥ | ' annamaśitaṃ tredhā vidhīyate tasya yaḥ sthaviṣṭho dhātustatpurīṣaṃ bhavati yo madhyamastanmāṃsaṃ yo'ṇiṣṭhastanmanaḥ' ityādiśrutyantaraprasiddhimādāyāśitasya jāṭharāgnipakvasya sthūlasūkṣmavibhāgaviniyojanakartā samāna iti vyutpādayati | atha yo'yaṃ prasiddho vāyuviśeṣo'nnasya bhuktasya sthaviṣṭhaḥ sthūlatamo dhāturasārabhāgaḥ purīṣākhyo yo'sti tamapāne prāpayati apānavāyusañcārasthānaṃ gamayati, tathā'nnasya yo vāsthvaṇiṣṭho'ṇutaro madhyamaścetibhāgadvayamekīkṛtyocyate, taṃ ca dehamanaḥsthitihetumaṅge'ṅge