गोविन्द भाष्य (श्रील बलदेव विद्याभूषण - अचिन्त्यभेदाभेद वेदान्त ब्रह्मसूत्र भाष्य सटीक)

and eternal, are all qualities of the Supreme Personality of Godhead.
Sūtra 19
na ca smārtam atad-dharmābhilāpāt
na—not; ca—and; smārtam—what is taught in the smṛti; atad—not of it;
dharma—the qualities; abhilāpāt—because of description.
The ruler within is not (the pradhāna, which is) described in the smṛti,
because the qualities (mentioned in this passage) cannot be attributed (to
pradhāna).
Purport by Śrīla Baladeva Vidyābhūṣaṇa
For these reasons it may not be said that the pradhāna, which is described in
the smṛti, is the ruler within. Why? The sūtra says atad-dharmābhilāpāt (because
the qualities mentioned in this passage cannot be attributed to it.
The Bṛhad-āraṇyaka Upaniṣad (3.7.23) says:
adṛṣṭo draṣṭā aśruto śrotā amato mantā avij{.sy 241}āto vijñātā nānyato 'sti draṣṭā
nānayto 'sti śrotā nānyato 'sti mantā nānyato 'sti vijñātaisa ta ātmāntaryāmy amṛta ito
'nyat smārtam
"Unobserved, He is the observer. Unheard, He is the hearer. Inconceivable, He
is the thinker. Unknown, he is the knower. There is no other observer. There is no
other hearer. there is no other thinker. There is no other knower. he is the
Supreme Personality of Godhead, the eternal ruler within. (The pradhāna)
described in the smṛti is different from Him."
The list of qualities here, beginning with being the observer, may be attributed
to the Supreme Personality of Godhead only.
Sūtra 20
śārīraś cobhaye 'pi hi bhedenainam adhīyate
śārīraḥ—the jīva; ca—also; ubhaye—in bothe recensions; api—also; hi—indeed;