योगवासिष्ठः yogavāsiṣṭhaḥ - book-6, chapter-107, verse-4

दिवा प्रीततरौ मित्रे यामिन्यामिष्टदंपती ।
प्रभादीपाविव श्लिष्टौ न वियुक्तौ बभूवतुः ॥ ४ ॥

divā prītatarau mitre yāminyāmiṣṭadaṃpatī ,
prabhādīpāviva śliṣṭau na viyuktau babhūvatuḥ 4

4. divā prītatarau mitre yāminyām iṣṭadampatī |
prabhādīpau iva śliṣṭau na viyuktau babhūvatuḥ || 4 ||

4. divā mitre prītatarau yāminyām iṣṭadampatī
prabhādīpau iva śliṣṭau na viyuktau babhūvatuḥ 4

4. By day, they were most delighted friends, and by night, a beloved couple. Like a lamp and its flame, they remained intertwined, never separated.

Words meanings summery:

• दिवा (divā) - by day, during the day

• प्रीततरौ (prītatarau) - more delighted, very pleased (dual)

• मित्रे (mitre) - two friends

• यामिन्याम् (yāminyām) - in the night, by night

• इष्टदम्पती (iṣṭadampatī) - a beloved couple, desired couple

• प्रभादीपौ (prabhādīpau) - a flame and a lamp (dual)

• इव (iva) - like, as, as if

• श्लिष्टौ (śliṣṭau) - united, embraced, joined

• न (na) - not

• वियुक्तौ (viyuktau) - separated, parted

• बभूवतुः (babhūvatuḥ) - they became

Words meanings and morphology

दिवा (divā) - by day, during the day

(indeclinable)

प्रीततरौ (prītatarau) - more delighted, very pleased (dual)

(adjective)

Nominative, masculine, dual of prītatara

prītatara - more pleased, more delighted (comparative of prīta)

Comparative degree formed with suffix -tara

मित्रे (mitre) - two friends

(noun)

Nominative, masculine, dual of mitra

mitra - friend, companion

यामिन्याम् (yāminyām) - in the night, by night

(noun)

Locative, feminine, singular of yāminī

yāminī - night

इष्टदम्पती (iṣṭadampatī) - a beloved couple, desired couple

(noun)

Nominative, masculine, dual of iṣṭadampati

iṣṭadampati - a desired or beloved couple

Compound type : karmadhāraya (iṣṭa+dampati)

• iṣṭa – desired, beloved, wished for
  adjective
  Past Passive Participle
  Root: iṣ (class 4)
• dampati – a married couple, husband and wife
  noun (masculine)

प्रभादीपौ (prabhādīpau) - a flame and a lamp (dual)

(noun)

Nominative, masculine, dual of prabhādīpa

prabhādīpa - a flame and a lamp (as a pair)

Compound type : dvandva (prabhā+dīpa)

• prabhā – light, radiance, splendor, flame
  noun (feminine)
• dīpa – lamp, light, lantern
  noun (masculine)

इव (iva) - like, as, as if

(indeclinable)

श्लिष्टौ (śliṣṭau) - united, embraced, joined

(adjective)

Nominative, masculine, dual of śliṣṭa

śliṣṭa - embraced, joined, united, clinging

Past Passive Participle

Root: śliṣ (class 1)

न (na) - not

(indeclinable)

वियुक्तौ (viyuktau) - separated, parted

(adjective)

Nominative, masculine, dual of viyukta

viyukta - separated, disjoined, parted

Past Passive Participle

Prefix: vi

Root: yuj (class 7)

बभूवतुः (babhūvatuḥ) - they became

(verb)

3rd person , dual, active, perfect (lit) of bhū

Root: bhū (class 1)