योगवासिष्ठः yogavāsiṣṭhaḥ - book-7, chapter-22, verse-3

अन्तःशीतलतेहासु प्राज्ञैर्यस्यावलोक्यते ।
अकृत्रिमैकशान्तस्य स ज्ञानीत्यभिधीयते ॥ ३ ॥

antaḥśītalatehāsu prājñairyasyāvalokyate ,
akṛtrimaikaśāntasya sa jñānītyabhidhīyate 3

3. antaḥśītalatehāsu prājñaiḥ yasya avalokyate
akṛtrimaikaśāntasya saḥ jñānī iti abhidhīyate

3. yasya prājñaiḥ antaḥśītalatehāsu avalokyate,
akṛtrimaikaśāntasya,
saḥ jñānī iti abhidhīyate

3. He is called a knower (jñānī) in whom the wise (prājñaiḥ) observe an inner serenity (antaḥśītalatā) even in activities (īhāsu), and whose singular peace (ekaśānta) is natural and unfeigned (akṛtrima).

Words meanings summery:

• अन्तःशीतलतेहासु (antaḥśītalatehāsu) - in the internal coolness of efforts, in the inner serenity of strivings

• प्राज्ञैः (prājñaiḥ) - by the wise ones, by the intelligent

• यस्य (yasya) - whose, of whom

• अवलोक्यते (avalokyate) - is seen, is observed, is perceived

• अकृत्रिमैकशान्तस्य (akṛtrimaikaśāntasya) - of the one whose singular peace is natural and unfeigned, of the spontaneously and uniquely peaceful one

• सः (saḥ) - he, that

• ज्ञानी (jñānī) - a knower, a wise person, one who possesses knowledge (jñāna)

• इति (iti) - thus, so, in this manner, marking direct speech or a conclusion

• अभिधीयते (abhidhīyate) - is called, is designated, is named

Words meanings and morphology

अन्तःशीतलतेहासु (antaḥśītalatehāsu) - in the internal coolness of efforts, in the inner serenity of strivings

(noun)

Locative, feminine, plural of antaḥśītalatehā

antaḥśītalatehā - internal coolness of efforts, inner serenity of strivings

Compound type : karmadhāraya (antas+śītalatā+īhā)

• antas – inside, internal, within
  indeclinable
• śītalatā – coolness, calmness, serenity
  noun (feminine)
• īhā – effort, striving, activity, endeavor
  noun (feminine)

प्राज्ञैः (prājñaiḥ) - by the wise ones, by the intelligent

(noun)

Instrumental, masculine, plural of prājña

prājña - wise, intelligent, skilled

Root: jñā (class 9)

यस्य (yasya) - whose, of whom

(pronoun)

Genitive, masculine, singular of yad

yad - which, what

अवलोक्यते (avalokyate) - is seen, is observed, is perceived

(verb)

3rd person , singular, passive, present (lat) of avalok

Prefix: ava

Root: lok (class 1)

अकृत्रिमैकशान्तस्य (akṛtrimaikaśāntasya) - of the one whose singular peace is natural and unfeigned, of the spontaneously and uniquely peaceful one

(adjective)

Genitive, masculine, singular of akṛtrimaikaśānta

akṛtrimaikaśānta - natural and singularly peaceful, unfeigned and uniquely calm

Compound type : karmadhāraya (akṛtrima+ekaśānta)

• akṛtrima – natural, unartificial, spontaneous, genuine
  adjective
  Negation (a-) of kṛtrima (artificial, made)
• ekaśānta – singularly peaceful, uniquely calm, solely tranquil
  adjective

सः (saḥ) - he, that

(pronoun)

Nominative, masculine, singular of tad

tad - that, he, she, it

ज्ञानी (jñānī) - a knower, a wise person, one who possesses knowledge (jñāna)

(noun)

Nominative, masculine, singular of jñānin

jñānin - a knower, a wise person, one who possesses knowledge

Derived from jñāna with the suffix -in.

Root: jñā (class 9)

इति (iti) - thus, so, in this manner, marking direct speech or a conclusion

(indeclinable)

अभिधीयते (abhidhīyate) - is called, is designated, is named

(verb)

3rd person , singular, passive, present (lat) of abhidhā

Prefix: abhi

Root: dhā (class 3)