योगवासिष्ठः yogavāsiṣṭhaḥ - book-5, chapter-14, verse-48

नाहं नेदमिति ध्यायंस्तिष्ठ त्वमचलाचलः ।
अनन्ताकाशसंकाशहृदयो हृदयेश्वरः ॥ ४८ ॥

nāhaṃ nedamiti dhyāyaṃstiṣṭha tvamacalācalaḥ ,
anantākāśasaṃkāśahṛdayo hṛdayeśvaraḥ 48

48. na aham na idam iti dhyāyan tiṣṭha tvam acala-acalaḥ
ananta-ākāśa-saṃkāśa-hṛdayaḥ hṛdaya-īśvaraḥ

48. iti na aham na idam dhyāyan,
tvam acala-acalaḥ tiṣṭha.
(tvam) ananta-ākāśa-saṃkāśa-hṛdayaḥ hṛdaya-īśvaraḥ (ca asi).

48. Meditating with the thought, 'I am not (this body), nor is this (world real)', remain utterly unwavering, with a heart (hṛdaya) resembling infinite space, the true master of your heart (hṛdaya).

Words meanings summery:

• न (na) - not, no

• अहम् (aham) - I

• न (na) - not, no

• इदम् (idam) - this (world/object) (this)

• इति (iti) - introduces a quote or thought (thus, so)

• ध्यायन् (dhyāyan) - meditating, contemplating, reflecting

• तिष्ठ (tiṣṭha) - stand, remain, abide

• त्वम् (tvam) - you

• अचल-अचलः (acala-acalaḥ) - absolutely unwavering (utterly unmoving, completely steady)

• अनन्त-आकाश-संकाश-हृदयः (ananta-ākāśa-saṁkāśa-hṛdayaḥ) - with a heart (hṛdaya) vast as infinite space (one whose heart resembles infinite space)

• हृदय-ईश्वरः (hṛdaya-īśvaraḥ) - the true master of your heart (hṛdaya) (lord of the heart, master of the heart)

Words meanings and morphology

न (na) - not, no

(indeclinable)

अहम् (aham) - I

(pronoun)

Nominative, singular of asmad

asmad - I, we

न (na) - not, no

(indeclinable)

इदम् (idam) - this (world/object) (this)

(pronoun)

Nominative, neuter, singular of idam

idam - this, this here

इति (iti) - introduces a quote or thought (thus, so)

(indeclinable)

ध्यायन् (dhyāyan) - meditating, contemplating, reflecting

(adjective)

Nominative, masculine, singular of dhyā

dhyā - to meditate, to contemplate, to think of

Present Active Participle

Root dhyā (to meditate).

Root: dhyā (class 1)

तिष्ठ (tiṣṭha) - stand, remain, abide

(verb)

2nd person , singular, active, imperative (lot) of sthā

Imperative Active

Root: sthā (class 1)

त्वम् (tvam) - you

(pronoun)

Nominative, singular of yuṣmad

yuṣmad - you (singular), you (plural)

अचल-अचलः (acala-acalaḥ) - absolutely unwavering (utterly unmoving, completely steady)

(adjective)

Nominative, masculine, singular of acala-acala

acala-acala - utterly unmoving, completely steady, perfectly still

Repetition of acala (immovable, steady) for emphasis.

Compound type : iterative (acala+acala)

• acala – immovable, steady, fixed
  adjective (masculine)
  From a- (not) + cala (moving).
  Prefix: a
  Root: cal (class 1)

अनन्त-आकाश-संकाश-हृदयः (ananta-ākāśa-saṁkāśa-hṛdayaḥ) - with a heart (hṛdaya) vast as infinite space (one whose heart resembles infinite space)

(adjective)

Nominative, masculine, singular of ananta-ākāśa-saṃkāśa-hṛdaya

ananta-ākāśa-saṁkāśa-hṛdaya - one whose heart is like infinite space

Compound type : bahuvrīhi (ananta-ākāśa-saṃkāśa+hṛdaya)

• ananta – infinite, endless
  adjective (masculine)
  From a- (not) + anta (end).
  Prefix: a
• ākāśa – space, ether, sky
  noun (masculine)
  Prefix: ā
  Root: kāś (class 1)
• saṃkāśa – resembling, like, similar to
  adjective (masculine)
  From sam-kāś (to appear like).
  Prefix: sam
  Root: kāś (class 1)
• hṛdaya – heart, mind, soul, core
  noun (neuter)

हृदय-ईश्वरः (hṛdaya-īśvaraḥ) - the true master of your heart (hṛdaya) (lord of the heart, master of the heart)

(noun)

Nominative, masculine, singular of hṛdaya-īśvara

hṛdaya-īśvara - lord of the heart, master of the heart

Compound type : tatpuruṣa (hṛdaya+īśvara)

• hṛdaya – heart, mind, soul, core
  noun (neuter)
• īśvara – lord, master, ruler; the Supreme Being
  noun (masculine)
  Root: īś (class 2)