1. The abode of heaven, earth, &c. (is the highest Self), on account of terms which are its own.
The followers of the Atharva-veda have the following text, 'He in whom the heaven, the earth and the sky are woven, the mind also, with all the vital airs, know him alone as the Self, and leave off other words; he is the bank (setu) of the Immortal' (Mu. Up. II, 2, 5). The doubt here arises whether the being spoken of as the abode of heaven, earth, and so on, is the individual soul or the highest Self.
The Pûrvapakshin maintains the former alternative. For, he remarks, in the next sloka, 'where like spokes in the nave of a wheel the arteries meet, he moves about within, becoming manifold, 'the word 'where' refers back to the being which in the preceding sloka had been called the abode of heaven, earth, and so on, the clause beginning with 'where' thus declaring that that being is the basis of the arteries; and the next clause declares that same being to become manifold or to be born in many ways. Now, connexion with the arteries is clearly characteristic of the individual soul; and so is being born in many forms, divine and so on. Moreover, in the very sloka under discussion it is said that that being is the abode of the mind and the five vital airs, and this also is a characteristic attribute of the individual soul. It being, on these grounds, ascertained that the text refers to the individual soul we must attempt to reconcile therewith, as well as we can, what is said about its being the abode of heaven, earth, &c.
This primâ facie view is set aside by the Sûtra. That which is described as the abode of heaven, earth, &c. is none other than the highest Brahman, on account of a term which is 'its own,' i.e. which specially belongs to it. The clause we have in view is 'he is the bank of the Immortal.' This description applies to the highest Brahman only, which
alone is, in all Upanishads, termed the cause of the attainment of Immortality; cp. e.g. 'Knowing him thus a man becomes immortal; there is no other path to go' (Sve. Up. III, 8). The term 'setu' is derived from si, which means to bind, and therefore means that which binds, i.e. makes one to attain immortality; or else it may be understood to mean that which leads towards immortality that lies beyond the ocean of samsâra, in the same way as a bank or bridge (setu) leads to the further side of a river.--Moreover the word 'Self (âtman) (which, in the text under discussion, is also applied to that which is the abode of heaven, earth. &c.), without any further qualification, primarily denotes Brahman only; for 'âtman' comes from âp, to reach, and means that which 'reaches' all other things in so far as it rules them. And further on (II, 2, 7) there are other terms, 'all knowing,' 'all cognising,' which also specially belong to the highest Brahman only. This Brahman may also be represented as the abode of the arteries; as proved e.g. by Mahânâr. Up. (XI, 8-12), 'Surrounded by the arteries he hangs... in the middle of this pointed flame there dwells the highest Self.' Of that Self it may also be said that it is born in many ways; in accordance with texts such as 'not born, he is born in many ways; the wise know the place of his birth.' For in order to fit himself to be a refuge for gods, men, &c. the supreme Person, without however putting aside his true nature, associates himself with the shape, make, qualities and works of the different classes of beings, and thus is born in many ways. Smriti says the same: 'Though being unborn, of non-perishable nature, the Lord of all beings, yet presiding over my Prakriti I am born by my own mysterious power' (Bha. Gî. IV, 6). Of the mind also and the other organs of the individual soul the highest Self is strictly the abode; for it is the abode of everything.--The next Sûtra supplies a further reason.