The Vedanta Sutras, commentary by Sankaracharya (SBE34), tr. by George Thibaut  at sacred-texts.com
14. The small (ether) (is Brahman) on account of the subsequent (arguments).
We read (Kh. Up. VIII, 1, 1),' There is this city of Brahman, and in it the palace, the small lotus, and in it that small ether. Now what exists within that small ether that is to be sought for, that is to be understood,' &c.--Here the doubt arises whether the small ether within the small lotus of the heart of which Scripture speaks, is the elemental ether, or the individual soul (vigñânâtman), or the highest Self. This doubt is caused by the words 'ether' and 'city of Brahman.' For the word 'ether,' in the first place, is known to be used in the sense of elemental ether as well as of highest Brahman. Hence the doubt whether the small ether of the text be the elemental ether or the highest ether, i. e. Brahman. In explanation of the expression 'city of Brahman,' in the second place, it might be said either that the individual soul is here called Brahman and the body Brahman's city, or else that the city of Brahman means the city of the highest Brahman. Here (i.e. in consequence of this latter doubt) a further doubt arises as to
the nature of the small ether, according as the individual soul or the highest Self is understood by the Lord of the city.
The pûrvapakshin maintains that by the small ether we have to understand the elemental ether, since the latter meaning is the conventional one of the word âkâsa. The elemental ether is here called small with reference to its small abode (the heart).--In the passage, 'As large as this ether is, so large is that ether within the heart,' it is represented as constituting at the same time the two terms of a comparison, because it is possible to make a distinction between the outer and the inner ether 1; and it is said that 'heaven and earth are contained within it,' because the whole ether, in so far as it is space, is one 2.--Or else, the pûrvapakshin continues, the 'small one' may be taken to mean the individual soul, on account of the term, 'the city of Brahman.' The body is here called the city of Brahman because it is the abode of the individual soul; for it is acquired by means of the actions of the soul. On this interpretation we must assume that the individual soul is here called Brahman metaphorically. The highest Brahman cannot be meant, because it is not connected with the body as its lord. The lord of the city, i.e. the soul, is represented as dwelling in one spot of the city (viz. the heart), just as a real king resides in one spot of his residence. Moreover, the mind (manas) constitutes the limiting adjunct of the individual soul, and the mind chiefly abides in the heart; hence the individual soul only can be spoken of as dwelling in the heart. Further, the individual soul only can be spoken of as small, since it is (elsewhere; Svet. Up. V, 8) compared in size to the point of a goad. That it is compared (in the passage under discussion) to the ether must be understood to intimate its non difference from Brahman.--
[paragraph continues] Nor does the scriptural passage say that the 'small' one is to be sought for and to be understood, since in the clause, 'That which is within that,' &c., it is represented as a mere distinguishing attribute of something else 1.
To all this we make the following reply:--The small ether can mean the highest Lord only, not either the elemental ether or the individual soul.--Why?--On account of the subsequent reasons, i. e. on account of the reasons implied in the complementary passage. For there, the text declares at first, with reference to the small ether, which is enjoined as the object of sight, 'If they should say to him,' &c.; thereupon follows an objection, 'What is there that deserves to be sought for or that is to be understood?' and thereon a final decisive statement, 'Then he should say: As large as this ether is, so large is that ether within the heart. Both heaven and earth are contained within it.' Here the teacher, availing himself of the comparison of the ether within the heart with the known (universal) ether, precludes the conception that the ether within the heart is small--which conception is based on the statement as to the smallness of the lotus, i. e. the heart--and thereby precludes the possibility of our understanding by the term 'the small ether,' the elemental ether. For, although the ordinary use of language gives to the word 'ether' the sense of elemental ether, here the elemental ether cannot be thought of, because it cannot possibly be compared with itself.--But, has it not been stated above, that the ether, although one only, may be compared with itself, in consequence of an assumed difference between the outer and the inner ether?--That explanation, we reply, is impossible; for we cannot admit that a comparison of a thing with itself may be based upon a merely imaginary difference. And even if we admitted
the possibility of such a comparison, the extent of the outer ether could never be ascribed to the limited inner ether. Should it be said that to the highest Lord also the extent of the (outer) ether cannot be ascribed, since another scriptural passage declares that he is greater than ether (Sa. Brâ, X, 6, 3, 2), we invalidate this objection by the remark, that the passage (comparing the inner ether with the outer ether) has the purport of discarding the idea of smallness (of the inner ether), which is primâ facie established by the smallness of the lotus of the heart in which it is contained, and has not the purport of establishing a certain extent (of the inner ether). If the passage aimed at both, a split of the sentence 1 would result.--Nor, if we allowed the assumptive difference of the inner and the outer ether, would it be possible to represent that limited portion of the ether which is enclosed in the lotus of the heart, as containing within itself heaven, earth, and so on. Nor can we reconcile with the nature of the elemental ether the qualities of Self-hood, freeness from sin, and so on, (which are ascribed to the 'small' ether) in the following passage, 'It is the Self free from sin, free from old age, from death and grief, from hunger and thirst, of true desires, of true purposes.'--Although the term 'Self' (occurring in the passage quoted) may apply to the individual soul, yet other reasons exclude all idea of the individual soul being meant (by the small ether). For it would be impossible to dissociate from the individual soul, which is restricted by limiting conditions and elsewhere compared to the point of a goad, the attribute of smallness attaching to it, on account of its being enclosed in the lotus of the heart.--Let it then be assumed--our opponent remarks--that the qualities of all-pervadingness, &c. are ascribed to the individual soul with the intention of intimating its non-difference from Brahman.--Well, we reply, if you suppose that the small ether is called all-pervading because it is one with Brahman, our own supposition,
viz. that the all-pervadingness spoken of is directly predicated of Brahman itself, is the much more simple one.--Concerning the assertion that the term 'city of Brahman' can only be understood, on the assumption that the individual soul dwells, like a king, in one particular spot of the city of which it is the Lord, we remark that the term is more properly interpreted to mean 'the body in so far as it is the city of the highest Brahman;' which interpretation enables us to take the term 'Brahman' in its primary sense 1. The highest Brahman also is connected with the body, for the latter constitutes an abode for the perception of Brahman 2. Other scriptural passages also express the same meaning, so, for instance, Pra. Up. V, 5, 'He sees the highest person dwelling in the city' (purusha = purisaya), &c., and Bri. Up. II, 5, 18, 'This person (purusha) is in all cities (bodies) the dweller within the city (purisaya).'--Or else (taking brahmapura to mean gîvapura) we may understand the passage to teach that Brahman is, in the city of the individual soul, near (to the devout worshipper), just as Vishnu is near to us in the Sâlagrâma-stone.--Moreover, the text (VIII, 1, 6) at first declares the result of works to be perishable ('as here on earth whatever has been acquired by works perishes, so perishes whatever is acquired for the next world by good actions,' &c.), and afterwards declares the imperishableness of the results flowing from a knowledge of the small ether, which forms the general subject of discussion ('those who depart from hence after having discovered the Self and those true desires, for them there is freedom in all worlds'). From this again it is manifest that the small ether is the highest Self.--We now turn to the statement made by the pûrvapakshin, 'that the sacred text does not represent the small ether as that
which is to be sought for and to be understood, because it is mentioned as a distinguishing attribute of something else,' and reply as follows: If the (small) ether were not that which is to be sought for and to be understood, the description of the nature of that ether, which is given in the passage ('as large as this ether is, so large is that ether within the heart'), would be devoid of purport.--But--the opponent might say--that descriptive statement also has the purport of setting forth the nature of the thing abiding within (the ether); for the text after having raised an objection (in the passage, 'And if they should say to him: Now with regard to that city of Brahman and the palace in it, i.e. the small lotus of the heart, and the small ether within the heart, what is there within it that deserves to be sought for or that is to be understood?') declares, when replying to that objection, that heaven, earth, and so on, are contained within it (the ether), a declaration to which the comparison with the ether forms a mere introduction.--Your reasoning, we reply, is faulty. If it were admitted, it would follow that heaven, earth, &c., which are contained within the small ether, constitute the objects of search and enquiry. But in that case the complementary passage would be out of place. For the text carrying on, as the subject of discussion, the ether that is the abode of heaven, earth, &c.--by means of the clauses, 'In it all desires are contained,' 'It is the Self free from sin,' &c., and the passage, 'But those who depart from hence having discovered the Self, and the true desires' (in which passage the conjunction 'and' has the purpose of joining the desires to the Self)--declares that the Self as well, which is the abode of the desires, as the desires which abide in the Self, are the objects of knowledge. From this we conclude that in the beginning of the passage also, the small ether abiding within the lotus of the heart, together with whatever is contained within it as earth, true desires, and so on, is represented as the object of knowledge. And, for the reasons explained, that ether is the highest Lord.
175:1 So that the interpretation of the pûrvapakshin cannot be objected to on the ground of its involving the comparison of a thing to itself.
175:2 So that no objection can be raised on the ground that heaven and earth cannot be contained in the small ether of the heart.
176:1 Viz. of that which is within it. Ânanda Giri proposes two explanations: na keti, paraviseshanatvenety atra paro daharâkâsa upâdânât tasminn iti saptamyanta-takkhabdasyeti seshah. Yadvâ parasabdo # ntahsthavastuvishayas tadviseshanatvena tasminn iti daharâkâsasyokter ity arthah. Takkhabdasya samnikrishtânvayayoge viprakrishtânvayasya gaghanyatvâd âkâsântargatam dhyeyam iti bhâvah.
177:1 A vâkyabheda--split of the sentence--takes place according to the Mîmâmsâ when one and the same sentence contains two new statements which are different.
178:1 While the explanation of Brahman by gîva would compel us to assume that the word Brahman secondarily denotes the individual soul.
Upalabdher adhishthânam brahmana deha ishyate