योगवासिष्ठः yogavāsiṣṭhaḥ - book-5, chapter-50, verse-15

चिरं संसरणाकाशकोटरं चित्तकुम्भखम् ।
विनाश्यातुलिताकाशस्वरूपं रूपमाविश ॥ १५ ॥

ciraṃ saṃsaraṇākāśakoṭaraṃ cittakumbhakham ,
vināśyātulitākāśasvarūpaṃ rūpamāviśa 15

15. ciram saṃsaraṇākāśakoṭaram cittakumbhakham
vināśya atulitākāśasvarūpam rūpam āviśa

15. Having destroyed the mind's pot-space, which has for a long time been the hollow cavity within the sky of transmigration (saṃsāra), enter your true nature, which is like the immeasurable (limitless) space.

Words meanings summery:

• चिरम् (ciram) - for a long time, long

• संसरणाकाशकोटरम् (saṁsaraṇākāśakoṭaram) - the hollow of the sky of transmigration

• चित्तकुम्भखम् (cittakumbhakham) - the mind's pot-space (the space of the mind, likened to a pot's interior)

• विनाश्य (vināśya) - having destroyed, annihilated

• अतुलिताकाशस्वरूपम् (atulitākāśasvarūpam) - whose nature is the immeasurable space, of the nature of limitless space

• रूपम् (rūpam) - form, nature, true essence

• आविश (āviśa) - enter, attain

Words meanings and morphology

चिरम् (ciram) - for a long time, long

(indeclinable)

Accusative singular neuter of 'cira' used adverbially.

संसरणाकाशकोटरम् (saṁsaraṇākāśakoṭaram) - the hollow of the sky of transmigration

(noun)

Accusative, neuter, singular of saṃsaraṇākāśakoṭara

saṁsaraṇākāśakoṭara - the hollow cavity which is the space of transmigration

Compound type : tatpuruṣa (saṃsaraṇa+ākāśa+koṭara)

• saṃsaraṇa – transmigration, wandering, flowing through
  noun (neuter)
  verbal noun
  from 'sam-' + '√sṛ' + '-ana' suffix
  Prefix: sam
  Root: sṛ (class 1)
• ākāśa – space, ether, sky
  noun (masculine)
  Prefix: ā
  Root: kāś (class 1)
• koṭara – hollow, cavity, hole
  noun (neuter)

Note: Object of 'vināśya'.

चित्तकुम्भखम् (cittakumbhakham) - the mind's pot-space (the space of the mind, likened to a pot's interior)

(noun)

Accusative, neuter, singular of cittakumbhakha

cittakumbhakha - the mind-space, the inner space of the mind (like the space in a pot)

Compound type : tatpuruṣa (citta+kumbhakha)

• citta – mind, consciousness
  noun (neuter)
  Root: cit (class 1)
• kumbhakha – space within a pot, pot-space
  noun (neuter)

Note: Object of 'vināśya'.

विनाश्य (vināśya) - having destroyed, annihilated

(indeclinable)

absolutive (gerund)

formed from 'vi-' + '√naś' (to perish, destroy) + '-ya' suffix for absolutive with prefix.

Prefix: vi

Root: naś (class 4)

अतुलिताकाशस्वरूपम् (atulitākāśasvarūpam) - whose nature is the immeasurable space, of the nature of limitless space

(adjective)

Accusative, neuter, singular of atulitākāśasvarūpa

atulitākāśasvarūpa - having the nature of immeasurable space

Compound type : bahuvrīhi (atulita+ākāśa+svarūpa)

• atulita – immeasurable, incomparable, unequalled
  adjective (neuter)
  Past Passive Participle
  from 'a-' + 'tu-' + '√tul' (to weigh, measure)
  Prefix: a
  Root: tul (class 10)
• ākāśa – space, ether, sky
  noun (masculine)
  Prefix: ā
  Root: kāś (class 1)
• svarūpa – one's own form or nature, essence
  noun (neuter)

Note: Modifies 'rūpam'.

रूपम् (rūpam) - form, nature, true essence

(noun)

Accusative, neuter, singular of rūpa

rūpa - form, shape, appearance, nature, beauty

Note: Object of 'āviśa'.

आविश (āviśa) - enter, attain

(verb)

2nd person , singular, active, imperative (lot) of ā-viś

imperative

second person singular imperative active of 'ā-√viś'.

Prefix: ā

Root: viś (class 6)