Dharmasya Param Guhyam
Śrī Manu in his Dharma Śāstra emphasis one who sees Self in every being attains the state of brahman.
Śrī Kṛṣṇa in Śrīmad Bhagavad Gītā (Chap 4.1) says I taught this immperishable knowledge, yoga to Sun, vivasvān (Sun shines equally on every being); who taught it to Manu; who gave this knowledge to Ikṣvāku, Śrī Rāma's ancestor.
इमम् विवस्वते योगं प्रोक्तवानहमव्ययम् ॥
विवस्वान्मनवे प्राह मनुरिक्ष्वाकवेऽब्रवित् ॥ —भ.गी.४.१
imam vivasvate yogaṁ
proktavān aham avyayam
vivasvān manave prāha
manur ikṣvākave abravit —bg.4.1
S. Radhakrishnan:- The Blessed Lord said: (1) I proclaimed this imperishable yoga to Vivasvān; Vivasvān told it to Manu and Manu spoke it to Ikṣvāku.
There is a reference in Mahābāra, Śāntiparva: 348; 51—52,
त्रेतायुगादौ च ततो विवसवान् मनवे ददौ मनुस् च लोकबृतयार्थं सुतायेक्षवाकवे ददौ इक्ष्वाकुणा च कथितो व्याप्य लोकान् अवस्थितः ।
tretāyugādau ca tato vivasvān manave dadau
manus ca lokabhṛtyarthaṁ sutāyekṣvākave dadau
ikṣvākuṇā ca kathito vyāpya lokān avasthitaḥ
These verses are the concluding verses of Manu's Dharma Sāśtra.
धर्मस्य परमं गुह्यं ममेदं सर्वमुक्तवान् ॥
सर्वमात्मनि सम्पश्येत् सत्चासत्च समाहितः
सर्वं ह्यात्मनि सम्पश्यन्नाधर्मे कुरुते मनः
dharmasya paramaṁ guhyaṁ
mamedaṁ sarvam uktavān ..
sarvamātmani sampaśyet
satcāsatca samāhitaḥ .
sarvaṁ hyātmani sampaśyan
na adharme kurute manaḥ ..
R. Nagaswamy:- I have said all about the supreme inner meaning of dharma of mine. One must see all these truth and untruth in ones own self with balanced mind. Having seen all in ones own self then one won't set his mind on adharma
एवं यः सर्वभूतेषु पश्यत्यात्मानमात्मना ।
स सर्वसमतामेत्य ब्रह्माभ्येति परं पदम् ॥
evaṁ yaḥ sarvabhūteṣu
paśyaty ātmānam ātmanā .
sa sarvasamatāmetya
brahmābhyeti paraṁ padam .
evam = thus, in this way; yaḥ = who; sarvabhūteṣu = in all beings; paśyat = sees; ātmānam = Self; ātmana = by the Self; sa = He; sarvasamatāmetya = sameness of level, dentity with; brahmābhyeti = attains the State of Brahman; paraṁ padam = the Supreme State;
इत्येतन् मानवं शास्त्रं भृगुप्रोक्तं पठन् द्विजः ।
भवत्याचारवान्नित्यं यथेष्टां प्राप्नुयाद् गतिम् ॥
ityetan mānavaṁ śāstraṁ
bhṛguproktaṁ paṭhan dvijaḥ .
bhavaty ācāravān nityaṁ
yatheṣṭāṁ prāpnuyād gatim ..
A verse in Manusmṛti, Bhagavad Gītā and Kaivalya Upaniṣad have an identical first foot (line). The second foot (line) expresses the same idea. Śrī Śaṅkara quotes the verse from Manusmṛti in his introduction to Viṣṇu Sahasranāma Bhāṣyam.
Manusmṛti - 12.91
सर्वभूतस्थम् आत्मानं सर्वभूतानि चात्मनि ।
[ v सर्वभूतेषु चात्मानं सर्वभूतानि चात्मनि ।]
समं पश्यन्नात्मयाजि [ वै ] स्वाराजयामदिगच्छति ॥ १२.९१ ॥
sarva-bhūtastham ātmānaṁ
sarva-bhūtāni cātmani .
samam paśyannātmayāji vai svārājyamadigachati .. 12.91
Śrī Kṛṣṇa, Gitā 6.29
सर्वभूतस्थम् आत्मानं सर्वभूतानि च अत्मनि ।
इक्सते योगयुक्तात्मा सर्वत्र समदर्शनः ॥
sarva-bhūtastham ātmānaṁ
sarva-bhūtāni ca ātmani .
ikṣate yoga-yuktātmā
sarvatra sama-darśanaḥ ..
S.Radhakrishna:- He whose self is harmonized by yoga seeth the Self abiding in all beings and all beings in the Self; everywhere he sees the same.
Kaivalya Upaniṣad, Stanza 10
सर्वभूतस्थम् आत्मानं सर्वभूतानि चात्मनि ।
सम्पश्यन् ब्रह्म परमं याति नान्येन हेतुना ॥
sarva-bhūtastham ātmānaṁ
sarva-bhūtāni cātmani .
sampaśyan brahma
paramaṁ yāti nānyena hetunā ..
S.Radhakrishna:- By seeing the self in all beings and all beings in the self one goes to Brahman, not by any other cause.