Brihadaranyaka Upanishad 1.29

एतं ह वाव ज्येष्ठं च श्रेष्ठं च वेद — ज्येष्ठश्च श्रेष्ठश्च स्वानां भवति — प्राणो ह वै ज्येष्ठश्च श्रेष्ठश्च ॥

etam ha vav jyeshtham cha shreshtham cha veda — jyeshthash cha shreshthash cha svanam bhavati — prano ha vai jyeshthash cha shreshthash cha ||

He who knows Prana as the eldest and the best becomes the eldest and the best among his own people. Prana is truly the eldest and the best.

जो इसे ज्येष्ठ और श्रेष्ठ जानता है, वह अपनों में ज्येष्ठ और श्रेष्ठ होता है। प्राण ही ज्येष्ठ और श्रेष्ठ है।