Chandogya Upanishad 8.3

यावान्वा अयमाकाशस्तावानेषोऽन्तर्हृदय आकाश उभे अस्मिन्द्यावापृथिवी अन्तरेव समाहिते उभावग्निश्च वायुश्च सूर्याचन्द्रमसावुभौ विद्युन्नक्षत्राणि यच्चास्येहास्ति यच्च नास्ति सर्वं तदस्मिन्समाहितमिति ॥ ३ ॥

8.1.3 — yavanva ayamakashastavanesho'ntarhridaya aakasha ubhe asmindyavaprithivi antareva samahite ubhavagnishcha vayushcha suryachandramasavubhau vidyunnakshatrani yachchasyehasti yachcha nasti sarvam tadasminsamahitamiti || 3 ||

Then he should say: 'As large as this ether (all space) is, so large is that ether within the heart. Both heaven and earth are contained within it, both fire and air, both sun and moon, both lightning and stars; and whatever there is of him (the Self) here in the world, and whatever is not (i. e. whatever has been or will be), all that is contained within it.

'जितना विशाल यह बाह्य आकाश है, उतना ही विशाल यह अन्तर्हृदय-आकाश है। द्यौ और पृथिवी दोनों इसी में समाहित हैं, अग्नि और वायु दोनों, सूर्य-चन्द्रमा दोनों, विद्युत्, नक्षत्र — और जो कुछ यहाँ इस जगत् में है अथवा नहीं है, वह सब इसी में समाहित है।'