AITAREYA UPANISHAD · 1.3.4

तत्प्राणेनाजिघृक्षत् तन्नाशक्नोत्प्राणेन ग्रहीतुं स यद्धैनत् प्राणेनाग्रहैष्यदभिप्राण्य हैवान्नमत्रप्स्यत् ॥ ४ ॥

tatprāṇenājighṛkṣat tannāśaknotprāṇena grahītuṃ sa yaddhainat prāṇenāgrahaiṣyadabhiprāṇya haivānnamatrapsyat ॥ 4 ॥

By the breath He would have seized it, but He could not seize it by the breath. Had He seized it by the breath, then would a man be satisfied by merely breathing food.