AITAREYA UPANISHAD · 1.3.7

तत्त्वचाजिघृक्षत् तन्नाशक्नोत्त्वचा ग्रहीतुं स यद्धैनत्त्वचाग्रहैष्यत् स्पृष्ट्वा हैवान्नमत्रप्स्यत् ॥ ७ ॥

tattvacājighṛkṣat tannāśaknottvacā grahītuṃ sa yaddhainattvacāgrahaiṣyat spṛṣṭvā haivānnamatrapsyat ॥ 7 ॥

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