The Vedanta Sutras, commentary by Sankaracharya (SBE34), tr. by George Thibaut  at sacred-texts.com
20. (The circumstance of the soul being represented as the object of sight) indicates the fulfilment of the promissory statement; so Âsmarathya thinks.
The fact that the text proclaims as the object of sight that Self which is denoted as something, dear indicates the fulfilment of the promise made in the passages, 'When the Self is known all this is known,' 'All this is that Self.' For if the individual soul were different from the highest Self, the knowledge of the latter would not imply the knowledge of the former, and thus the promise that through the knowledge of one thing everything is to be known would not be fulfilled. Hence the initial
statement aims at representing the individual Self and the highest Self as non-different for the purpose of fulfilling the promise made.--This is the opinion of the teacher Âsmarathya 1.
277:1 The comment of the Bhâmatî on the Sûtra runs as follows: As the sparks issuing from a fire are not absolutely different from the fire, because they participate in the nature of the fire; and, on the other hand, are not absolutely non-different from the fire, because in that case they could be distinguished neither from the fire nor from each other; so the individual souls also--which are effects of Brahman--are neither absolutely different from Brahman, for that would mean that they are not of the nature of intelligence; nor absolutely non-different from Brahman, because in that case they could not be distinguished from each other, and because, if they were identical with Brahman and therefore omniscient, it would be useless to give them any instruction. Hence the individual souls are somehow different from Brahman and somehow non-different.--The technical name of the doctrine here represented by Âsmarathya is bhedâbhedavâda.