The Vedanta Sutras of Badarayana, Commentary by Sankara (SBE38), tr. by George Thibaut  at sacred-texts.com
29. Or else (the relation of the two is to be conceived) in the manner stated above.
Or else the relation of the two has to be conceived in the manner suggested by Sûtra 25. For if the bondage of the soul is due to Nescience only, final release is possible. But if the soul is really and truly bound--whether the soul be considered as a certain condition or state of the highest Self as suggested in Sûtra 27, or as a part of the highest Self as suggested in Sûtra 28--its real bondage cannot be done away with, and thus the scriptural doctrine of final release becomes absurd.--Nor, finally, can it be said that Sruti equally teaches difference and non-difference. For non-difference only is what it aims at establishing; while, when engaged in setting forth something else, it merely refers to difference as something known from other sources of knowledge (viz. perception, &c.).--Hence the conclusion stands that the soul is not different from the highest Self, as explained in Sûtra 25.