CHĀNDOGYA UPANISHAD · 6.8.4

तस्य क्व मूलं स्याद् अन्यत्रान्नात् ।
एवम् एव खलु सोम्यान्नेन शुङ्गेनापो मूलम् अन्विच्छ ।
अद्भिः सोम्य शुङ्गेन तेजो मूलम् अन्विच्छ ।
तेजसा सोम्य शुङ्गेन सन्मूलम् अन्विच्छ ।
सन्मूलाः सोम्येमाः सर्वाः प्रजाः सदायतनाः सत्प्रतिष्ठाः ॥

tasya kva mūlaṃ syād anyatrānnāt ।
evam eva khalu somyānnena śuṅgenāpo mūlam anviccha ।
adbhiḥ somya śuṅgena tejo mūlam anviccha ।
tejasā somya śuṅgena sanmūlam anviccha ।
sanmūlāḥ somyemāḥ sarvāḥ prajāḥ sadāyatanāḥ satpratiṣṭhāḥ ॥

'And where could its root be except in food (earth)? And in the same manner, my son, as food (earth) too is an offshoot, seek after its root, viz. water. And as water too is an offshoot, seek after its root, viz. fire. And as fire too is an offshoot, seek after its root, viz. the True. Yes, all these creatures, my son, have their root in the True, they dwell in the True, they rest in the True.

F. Max Müller · The Upanishads, Sacred Books of the East 1 (1879)