Chandogya Upanishad 6.9

कुतस्तु खलु सोम्यैवँस्यादिति होवाच कथमसतः सज्जायेतेति। सत्त्वेव सोम्येदमग्र आसीदेकमेवाद्वितीयम् ॥ २ ॥

6.2.2 — kutastu khalu somyaivansyaditi hovacha kathamasatah sajjayeteti| sattveva somyedamagra aasidekamevadvitiyam || 2 ||

'But how could it be thus, my dear?' the father continued. 'How could that which is, be born of that which is not? No, my dear, only that which is, was in the beginning, one only, without a second.

'परन्तु हे सौम्य, यह कैसे सम्भव है?' — उसने कहा। 'असत् से सत् कैसे उत्पन्न हो सकता है? नहीं, हे सौम्य, आरम्भ में केवल सत् ही था — एक ही, अद्वितीय।'