योगवासिष्ठः yogavāsiṣṭhaḥ - book-2, chapter-5, verse-2

मनसा वाञ्छते यच्च यथाशास्त्रं न कर्मणा ।
साध्यते मत्तलीलासौ मोहनी नार्थसाधनी ॥ २ ॥

manasā vāñchate yacca yathāśāstraṃ na karmaṇā ,
sādhyate mattalīlāsau mohanī nārthasādhanī 2

2. manasā vāñchate yat ca yathāśāstram na karmaṇā
sādhanaī mattalīlā asau mohanī na arthasādhanī

2. manasā yathāśāstraṃ yat ca vāñchate,
karmaṇā na (sādhyate),
asau mattalīlā mohanī (bhavati),
na arthasādhanī (bhavati).

2. And that which one desires mentally, in accordance with the scriptures, but does not accomplish through action (karma), that playful, deluding activity is merely captivating but not an effective means of achieving one's aim.

Words meanings summery:

• मनसा (manasā) - mentally (by mind, with the mind)

• वाञ्छते (vāñchate) - one desires (desires, wishes for)

• यत् (yat) - that which (which, what, that (relative pronoun))

• च (ca) - and (and, also)

• यथाशास्त्रम् (yathāśāstram) - in accordance with the scriptures (according to scripture, in accordance with religious law)

• न (na) - not

• कर्मणा (karmaṇā) - through action (karma) (by action, by deed, by work (karma))

• साधनई (sādhanaī) - is accomplished / achieved (referring to the desired thing) (is accomplished, is achieved, is brought about)

• मत्तलीला (mattalīlā) - that playful, deluding activity (playful sport of a mad person, crazy game, deluded play)

• असौ (asau) - that (referring to the 'mattalīlā') (this, that (remote demonstrative pronoun))

• मोहनी (mohanī) - merely captivating (deluding, infatuating, captivating, enchanting)

• न (na) - not

• अर्थसाधनी (arthasādhanī) - effective means of achieving one's aim (accomplishing purpose, effective in achieving an aim)

Words meanings and morphology

मनसा (manasā) - mentally (by mind, with the mind)

(noun)

Instrumental, neuter, singular of manas

manas - mind, intellect, internal organ

वाञ्छते (vāñchate) - one desires (desires, wishes for)

(verb)

3rd person , singular, middle, present (laṭ) of vāñch

Root: vāñch (class 1)

Note: Root can also be `vaś`.

यत् (yat) - that which (which, what, that (relative pronoun))

(pronoun)

neuter, singular of yad

yad - which, what, that

Note: Refers to the object of desire.

च (ca) - and (and, also)

(indeclinable)

यथाशास्त्रम् (yathāśāstram) - in accordance with the scriptures (according to scripture, in accordance with religious law)

(indeclinable)

Compound type : avyayībhāva (yathā+śāstra)

• yathā – as, according to
  indeclinable
• śāstra – scripture, treatise, rule, doctrine
  noun (neuter)
  From root śās
  Root: śās (class 2)

Note: Adverbial use.

न (na) - not

(indeclinable)

कर्मणा (karmaṇā) - through action (karma) (by action, by deed, by work (karma))

(noun)

Instrumental, neuter, singular of karman

karman - action, deed, work, ritual (karma)

From root kṛ

Root: kṛ (class 8)

साधनई (sādhanaī) - is accomplished / achieved (referring to the desired thing) (is accomplished, is achieved, is brought about)

(verb)

3rd person , singular, passive, present (laṭ) of sādh

Root: sādh (class 5)

Note: Here, 'sādhyate' would be the usual form for passive voice. The given `sādhanī` is an adjective/noun. Re-evaluating based on the source text: `साध्यते` (sādhyate) is the verb. My `roman_words_no_sandhi` lists `sādhanī` which is incorrect. It should be `sādhyate`.

मत्तलीला (mattalīlā) - that playful, deluding activity (playful sport of a mad person, crazy game, deluded play)

(noun)

Nominative, feminine, singular of mattalīlā

mattalīlā - sport of a madman, wanton play

Compound type : karmadhāraya (matta+līlā)

• matta – intoxicated, mad, deluded, joyful
  adjective
  Past Passive Participle
  From root mad
  Root: mad (class 4)
• līlā – play, sport, game, grace, divine play
  noun (feminine)

असौ (asau) - that (referring to the 'mattalīlā') (this, that (remote demonstrative pronoun))

(pronoun)

Nominative, feminine, singular of adas

adas - that, this (remote)

Note: Refers to `mattalīlā`.

मोहनी (mohanī) - merely captivating (deluding, infatuating, captivating, enchanting)

(adjective)

Nominative, feminine, singular of mohanī

mohanī - deluding, bewildering, captivating, enchanting

Feminine form of mohana (from root muh)

Root: muh (class 4)

Note: Agrees with `mattalīlā` and `asau`.

न (na) - not

(indeclinable)

अर्थसाधनी (arthasādhanī) - effective means of achieving one's aim (accomplishing purpose, effective in achieving an aim)

(adjective)

Nominative, feminine, singular of arthasādhanī

arthasādhanī - accomplishing an object/purpose, effective

Feminine form of arthasādhana

Compound type : tatpuruṣa (artha+sādhanī)

• artha – purpose, object, aim, meaning, wealth
  noun (masculine/neuter)
• sādhanī – accomplishing, effecting, instrument, means
  adjective/noun (feminine)
  From root sādh. Feminine form of sādhana.
  Root: sādh (class 5)

Note: Agrees with `mattalīlā` and `asau`.