The Vedanta Sutras, commentary by Sankaracharya (SBE34), tr. by George Thibaut  at sacred-texts.com
2. And on account of its being designated as that to which the Released have to resort.
By the abode of heaven, earth, and so on, we have to understand the highest Brahman for that reason also that we find it denoted as that to which the Released have to resort.--The conception that the body and other things contained in the sphere of the Not-self are our Self, constitutes Nescience; from it there spring desires with regard to whatever promotes the well-being of the body and so on, and aversions with regard to whatever tends to injure it; there further arise fear and confusion when we observe anything threatening to destroy it. All this constitutes an endless series of the most manifold evils with which we all are acquainted. Regarding those on the other hand who have freed themselves from the stains of Nescience desire aversion and so on, it is said that they have to resort to that, viz. the abode of heaven, earth, &c. which forms the topic of discussion. For the text, after having said, 'The fetter of the heart is broken, all doubts are solved, all his works perish when He has been beheld who is the higher and the lower' (Mu. Up. II, 2, 8), later on remarks, 'The wise man freed from name and form goes to the divine Person who is greater than the great' (Mu. Up. III, 2, 8). That Brahman is that which is to be resorted to by the released, is known from other scriptural passages, such as 'When all desires which once entered his heart are undone then does the mortal become immortal, then he obtains Brahman' (Bri. Up. IV, 4, 7). Of the pradhâna and similar entities, on the other hand, it is not known from any source that they are to be resorted to by the released. Moreover, the text (in the passage, 'Know him alone as the Self and leave off other words') declares that the knowledge of the abode of heaven and earth, &c. is connected with the leaving off of all speech; a condition which, according to another scriptural passage, attaches to (the knowledge of) Brahman; cp. Bri. Up. IV, 4, 21, 'Let a wise Brâhmana, after he has discovered him, practise wisdom. Let him not seek after many words, for that is mere weariness of the tongue.'--For that
reason also the abode of heaven, earth, and so on, is the highest Brahman.