As this footnote in the Motilal Banarsidass translation says, it just refers to the preceding verses (8A-16) in the same chapter:
Description of Manvantaras
8A. With his vision uninterrupted, this Vāsudeva dwells in all bodies. He does not perceive the (evolution, continuance and dissolution of) universe with the help of another. He is the cause of the (sentient and nonsentient) universe. Hence
his vision (and power of controlling from within).
BhP_08.01.009/1 yena cetayate viśvaṃ viśvaṃ cetayate na yam
BhP_08.01.009/3 yo jāgarti śayāne 'smin nāyaṃ taṃ veda veda saḥ
9. By him the universe is endowed with consciousness, but unto whom (none in) the universe (can) impart consciousness. He remains awake (as a witness) while the universe is
in sleep (even during Pralaya). No creatures can know him but he knows all. (He is the ātman).
BhP_08.01.010/1 ātmāvāsyamidaṃ viśvaṃ yat kiñcij jagatyāṃ jagat
BhP_08.01.010/3 tena tyaktena bhuñjīthā mā gṛdhaḥ kasya sviddhanam
10. Whatever is animate (and inanimate) in this universe, — the whole universe is pervaded by the Supreme Soul. Therefore you should make your living by whatever has been allotted to you by him (or what is given to you, after offering it to him). Do not covet another person’s riches.
* The next verses are based on Upaniṣadic texts and are known as Mantropaniṣad.
Verse 10, for example, is based on the first verse of Īśopaniṣad:
īśāvāsyamidaṃ sarvaṃ yatkiñca jagatyāṃ jagat |
tena tyaktena bhuñjīthā mā gṛdhaḥ kasyasviddhanam ||
Whatever there is changeful in this ephemeral world, all that must be enveloped by the Lord. By this renunciation, support yourself. Do not covet the wealth of anyone.
BTW, the same word is also used in the 6th Canto and as noted in the translation, it refers to another set of mantras in the next chapter (Ch. 16, verses 18-25) which Nārada imparts to King Citraketu.
BhP_06.15.027/0 śrīnārada uvāca
BhP_06.15.027/1 etāṃ mantropaniṣadaṃ pratīccha prayato mama
BhP_06.15.027/2 yāṃ dhārayan saptarātrāddraṣṭā saṅkarṣaṇaṃ vibhum
- After purifying yourself (i.e. after disposing of the dead body of the child and taking a bath thereafter) accept from me the Mantropaniṣad (Vide Infra Ch. XVI, 18-25). By bearing this in mind and meditating over it, you will visualize Lord Saṅkarṣaṇa within seven nights.
And here are those mantras and their translation:
BhP_06.16.018/1 oṃ namastubhyaṃ bhagavate vāsudevāya dhīmahi
BhP_06.16.018/2 pradyumnāyāniruddhāya namaḥ saṅkarṣaṇāya ca
BhP_06.16.019/1 namo vijñānamātrāya paramānandamūrtaye
BhP_06.16.019/2 ātmārāmāya śāntāya nivṛttadvaitadṛṣṭaye
BhP_06.16.020/1 ātmānandānubhūtyaiva nyastaśaktyūrmaye namaḥ
BhP_06.16.020/2 hṛṣīkeśāya mahate namaste 'nantamūrtaye
BhP_06.16.021/1 vacasy uparate 'prāpya ya eko manasā saha
BhP_06.16.021/2 anāmarūpaścinmātraḥ so 'vyān naḥ sadasatparaḥ
BhP_06.16.022/1 yasminnidaṃ yataścedaṃ tiṣṭhaty apyeti jāyate
BhP_06.16.022/2 mṛṇmayeṣviva mṛjjātistasmai te brahmaṇe namaḥ
BhP_06.16.023/1 yan na spṛśanti na vidurmanobuddhīndriyāsavaḥ
BhP_06.16.023/2 antarbahiśca vitataṃ vyomavat tan nato 'smy aham
BhP_06.16.024/1 dehendriyaprāṇamanodhiyo 'mī yadaṃśaviddhāḥ pracaranti karmasu
BhP_06.16.024/2 naivānyadā lauhamivāprataptaṃ sthāneṣu taddraṣṭrapadeśameti
BhP_06.16.025/1 oṃ namo bhagavate mahāpuruṣāya mahānubhāvāya mahāvibhūtipataye sakalasātvataparivṛḍhanikarakarakamalakuḍmalopalālitacaraṇāravindayugala paramaparameṣṭhin namaste
OM! Salutation unto you, oh glorious Lord Vāsudeva. We contemplate (mentally pay obeisance to) you. We bow to Pradyumna, Aniruddha and Saṅkarṣaṇa (all the vyūhas of the Lord).
Obeisance to You who are pure, absolute knowledge, the very embodiment of supreme bliss, delighted with yourself, serene and above the notion of duality.
Hail to you who, through realization of your blissful character, kept yourself above the waves (the feelings of love, hate etc.) caused by Māyā. Salutation to the great Hṛṣīkeśa (the Supreme Master of Senses) whose body is the universe.
May he protect us — he who shines alone by himself and is beyond the reach of speech and other senses and the mind; who is pure consciousness and has no name or form and who is the cause of the law of causation (and hence above it) .
Bow to you Supreme Brahman on whom the universe (the product of cause and effect) is based, from whom it evolves and in whom it dissolves and thus pervades everything in the universe, just as products of earth do with reference to the earth.
I salute the Brahman which pervades everything from within and without like the sky but to whom the Prānas (organs of activity) do not touch (by their conative force) nor do the mind, intellect and cognitive senses comprehend him (by their power of cognition).
It is only when these—body, senses, vital airs, mind and intellect—are charged by his part or presence (aṃśa) that these carry out their functions and not otherwise, just as an unheated piece of iron (does not emit heat or light.) What is called the 'spectator' is another designation of yours in the slate of wakefulness (of the Jīva. He has no independent existence apart from you).
Salutations to you the Supreme Person, designated by the sacred symbol OM, the possessor of Supreme Might, whose lotus-like feet are adored in great love with the lotus-bud-like joined palms by all the great Sātvatas (votaries of the Lord). I reverentially bow to you, the most excellent controller of all.