योगवासिष्ठः yogavāsiṣṭhaḥ - book-3, chapter-25, verse-7

असुरस्त्रैणवल्लर्या संभोगसुकुमारया ।
प्राप्यभूभृन्महाबीजहृदयं भूतबीजया ॥ ७ ॥

asurastraiṇavallaryā saṃbhogasukumārayā ,
prāpyabhūbhṛnmahābījahṛdayaṃ bhūtabījayā 7

7. asura-straiṇa-vallaryā saṃbhoga-sukumārayā
prāpya-bhūbhṛt-mahābīja-hṛdayam bhūta-bījayā

7. prāpya-bhūbhṛt-mahābīja-hṛdayam asura-straiṇa-vallaryā
saṃbhoga-sukumārayā bhūta-bījayā

7. The heart, which is the great seed of kings/mountains, is to be attained by the creeper-like women of asuras, by those delicate in union, and by the seed of all beings.

Words meanings summery:

• असुर-स्त्रैण-वल्लर्या (asura-straiṇa-vallaryā) - by the creeper of asura women, by the vine of demonic women

• संभोग-सुकुमारया (saṁbhoga-sukumārayā) - by the one delicate in union, by the one tender in enjoyment

• प्राप्य-भूभृत्-महाबीज-हृदयम् (prāpya-bhūbhṛt-mahābīja-hṛdayam) - the heart of the great seed of kings/mountains to be attained

• भूत-बीजया (bhūta-bījayā) - by the seed of beings, by the seed of elements

Words meanings and morphology

असुर-स्त्रैण-वल्लर्या (asura-straiṇa-vallaryā) - by the creeper of asura women, by the vine of demonic women

(noun)

Instrumental, feminine, singular of asura-straiṇa-vallarī

asura-straiṇa-vallarī - creeper of asura women, vine of demonic women

Compound type : tatpuruṣa (asura+straiṇa+vallarī)

• asura – demon, anti-god
  noun (masculine)
• straiṇa – feminine, relating to women, group of women
  adjective
  derived from strī (woman)
• vallarī – creeper, vine
  noun (feminine)

संभोग-सुकुमारया (saṁbhoga-sukumārayā) - by the one delicate in union, by the one tender in enjoyment

(adjective)

Instrumental, feminine, singular of saṃbhoga-sukumārā

saṁbhoga-sukumārā - delicate in union, tender in enjoyment

Compound type : bahuvrīhi (saṃbhoga+sukumārā)

• saṃbhoga – union, embrace, enjoyment, sexual intercourse
  noun (masculine)
  from sam-bhuj
  Prefix: sam
  Root: bhuj (class 7)
• sukumārā – very tender, delicate, soft, lovely
  adjective
  from su (good/very) + kumāra (tender/young)

Note: refers to a feminine entity

प्राप्य-भूभृत्-महाबीज-हृदयम् (prāpya-bhūbhṛt-mahābīja-hṛdayam) - the heart of the great seed of kings/mountains to be attained

(noun)

Accusative, neuter, singular of prāpya-bhūbhṛt-mahābīja-hṛdaya

prāpya-bhūbhṛt-mahābīja-hṛdaya - the heart/essence that is the great seed of kings/mountains and is to be attained

Compound type : tatpuruṣa (prāpya+bhūbhṛt+mahābīja+hṛdaya)

• prāpya – to be obtained, attainable, to be reached
  adjective
  Gerundive
  from pra-āp (to obtain) + ya (gerundive suffix)
  Prefix: pra
  Root: āp (class 5)
• bhūbhṛt – earth-bearer, mountain, king
  noun (masculine)
  from bhū (earth) + bhṛ (to bear)
  Root: bhṛ (class 3)
• mahābīja – great seed, great source
  noun (neuter)
• hṛdaya – heart, core, essence, mind
  noun (neuter)

भूत-बीजया (bhūta-bījayā) - by the seed of beings, by the seed of elements

(noun)

Instrumental, feminine, singular of bhūta-bīja

bhūta-bīja - seed of beings, source of elements

Compound type : tatpuruṣa (bhūta+bīja)

• bhūta – being, creature, element, past
  noun
  Past Passive Participle
  from bhū (to be)
  Root: bhū (class 1)
• bīja – seed, germ, origin, cause
  noun (neuter)

Note: feminine form of bhūtabīja (neuter default) used here, likely referring to a feminine power or entity as the 'seed of beings'