Chandogya Upanishad 6.32

षोडशकलः सोम्य पुरुषः पञ्चदशाहानि माशीः काममपः पिबापोमयः प्राणो नपिबतो विच्छेत्स्यत इति ॥ १ ॥

6.7.1 — shodashakalah somya purushah panchadashahani mashih kamamapah pibapomayah prano napibato vichchhetsyata iti || 1 ||

'Man (purusha), my son, consists of sixteen parts. Abstain from food for fifteen days, but drink as much water as you like, for breath comes from water, and will not be cut off, if you drink water.'

'हे सौम्य, पुरुष षोडशकल (सोलह-कला वाला) है। तू पन्द्रह दिन अन्न-त्याग कर; इच्छानुसार जल पीता रह — क्योंकि प्राण जलमय है, और जलपान करते रहने से प्राण नहीं टूटेगा।'