Part 1 is included in Chandogya Upanishad (chapters 6 to 8) Part14
BSB 1.3.14 to 1.3.21 Ch 8.1.1 reads: “Om. Now, in this city of Brahman, there is a mansion in the shape of a small Lotus; in it is a small inner Ākāśa. What is within that, that should be sought; that, indeed, one should desire to understand.” [Swami Swahananda. Chandogya Upanisad (p. 366). RK Math, Mylapore, Chennai. Kindle Edition.] There is a doubt whether term ‘Akasa’ (space) refers to material space or Brahman. Another doubt is about the owner of the ‘city’, Brahman or the individual soul. The opponent holds that space denotes material space because the text, “the space inside the heart is of the same magnitude as the space outside” (Ch 8.1.3) is meaningful only for material space. The individual soul is the owner of the city because the body is earned on account of action of the individual soul. The aphorist rejects the views of the opponent on the strength of Ch 8.1.2 and Ch 8.1.3.