महाभारतः mahābhārataḥ - book-12, chapter-113, verse-18

बुद्धिश्रेष्ठानि कर्माणि बाहुमध्यानि भारत ।
तानि जङ्घाजघन्यानि भारप्रत्यवराणि च ॥१८॥

18. buddhiśreṣṭhāni karmāṇi bāhumadhyāni bhārata ,
tāni jaṅghājaghanyāni bhārapratyavarāṇi ca.

18. buddhi-śreṣṭhāni karmāṇi bāhu-madhyāni bhārata
tāni jaṅghā-jaghanyāni bhāra-pratyavarāṇi ca

18. bhārata karmāṇi buddhi-śreṣṭhāni bāhu-madhyāni
tāni jaṅghā-jaghanyāni bhāra-pratyavarāṇi ca

18. O Bhārata, actions (karma) are best when intelligence is supreme; middling when physical strength is central; and lowest when they involve mere movement (legs) or carrying burdens.

Words meanings summery:

• बुद्धि-श्रेष्ठानि (buddhi-śreṣṭhāni) - best in intelligence, having intelligence as supreme

• कर्माणि (karmāṇi) - actions, deeds, works

• बाहु-मध्यानि (bāhu-madhyāni) - having arms/strength as middling, mediocre in physical strength

• भारत (bhārata) - Addressed to Arjuna, as a descendant of King Bharata. (O Bhārata (descendant of Bharata, here Arjuna))

• तानि (tāni) - those

• जङ्घा-जघन्यानि (jaṅghā-jaghanyāni) - lowest in legs/movement, having legs as the lowest part

• भार-प्रत्यवराणि (bhāra-pratyavarāṇi) - lowest due to burdens, inferior in terms of burdens

• च (ca) - and

Words meanings and morphology

बुद्धि-श्रेष्ठानि (buddhi-śreṣṭhāni) - best in intelligence, having intelligence as supreme

(adjective)

Nominative, neuter, plural of buddhiśreṣṭha

buddhiśreṣṭha - having intelligence as the best part, supremely intelligent

Compound type : Bahuvrīhi (buddhi+śreṣṭha)

• buddhi – intelligence, intellect, understanding
  noun (feminine)
  Root: budh (class 1)
• śreṣṭha – best, excellent, supreme, most distinguished
  adjective (masculine)

कर्माणि (karmāṇi) - actions, deeds, works

(noun)

Nominative, neuter, plural of karman

karman - action, deed, work, ritual, fate, consequence of actions

Root: kṛ (class 8)

बाहु-मध्यानि (bāhu-madhyāni) - having arms/strength as middling, mediocre in physical strength

(adjective)

Nominative, neuter, plural of bāhumadhya

bāhumadhya - having arms or physical strength as the middle part or main feature; middling

Compound type : Bahuvrīhi (bāhu+madhya)

• bāhu – arm, fore-arm, strength
  noun (masculine)
• madhya – middle, central, intermediate, mediocre
  adjective (neuter)

भारत (bhārata) - Addressed to Arjuna, as a descendant of King Bharata. (O Bhārata (descendant of Bharata, here Arjuna))

(proper noun)

Vocative, masculine, singular of bhārata

bhārata - descendant of Bharata, Indian

तानि (tāni) - those

(pronoun)

Nominative, neuter, plural of tad

tad - that, those

जङ्घा-जघन्यानि (jaṅghā-jaghanyāni) - lowest in legs/movement, having legs as the lowest part

(adjective)

Nominative, neuter, plural of jaṅghājaghanya

jaṅghājaghanya - whose legs are the lowest or least important part; inferior due to physical movement/speed

Compound type : Bahuvrīhi (jaṅghā+jaghanya)

• jaṅghā – leg, thigh, lower leg (symbolizing swiftness or physical movement)
  noun (feminine)
• jaghanya – lowest, last, inferior, contemptible
  adjective (neuter)

भार-प्रत्यवराणि (bhāra-pratyavarāṇi) - lowest due to burdens, inferior in terms of burdens

(adjective)

Nominative, neuter, plural of bhārapratyavara

bhārapratyavara - inferior on account of burdens, lowest due to carrying loads

Compound type : Bahuvrīhi (bhāra+pratyavara)

• bhāra – burden, load, weight
  noun (masculine)
  Root: bhṛ (class 1)
• pratyavara – lowest, inferior, mean, vile
  adjective (neuter)
  Prefix: prati

च (ca) - and

(indeclinable)