महाभारतः mahābhārataḥ - book-12, chapter-309, verse-42

पुरा वृका भयंकरा मनुष्यदेहगोचराः ।
अभिद्रवन्ति सर्वतो यतस्व पुण्यशीलने ॥४२॥

42. purā vṛkā bhayaṁkarā manuṣyadehagocarāḥ ,
abhidravanti sarvato yatasva puṇyaśīlane.

42. purā vṛkā bhayaṅkarā manuṣyadehagocarāḥ
abhidravanti sarvataḥ yatasva puṇyaśīlane

42. purā bhayaṅkarāḥ manuṣyadehagocarāḥ vṛkāḥ
sarvataḥ abhidravanti puṇyaśīlane yatasva

42. Before the terrifying 'wolves' (vṛkāḥ), which prey on the human body (manuṣyadehagocarāḥ), attack from all sides, strive in the practice of virtue.

Words meanings summery:

• पुरा (purā) - before (before; formerly; in the past; beforehand)

• वृकाः (vṛkāḥ) - the 'wolves' (vṛkāḥ) (metaphorical for vices) (wolves)

• भयङ्कराः (bhayaṅkarāḥ) - terrifying (terrifying; fearful; causing fear)

• मनुष्यदेहगोचराः (manuṣyadehagocarāḥ) - which prey on the human body (which move in the human body; whose domain is the human body; preying on the human body)

• अभिद्रवन्ति (abhidravanti) - attack (they attack; they rush towards; they assail)

• सर्वतः (sarvataḥ) - from all sides (from all sides; everywhere; completely)

• यतस्व (yatasva) - strive (strive; endeavor; exert yourself)

• पुण्यशीलने (puṇyaśīlane) - in the practice of virtue (in the practice of virtue; in the cultivation of merit)

Words meanings and morphology

पुरा (purā) - before (before; formerly; in the past; beforehand)

(indeclinable)

वृकाः (vṛkāḥ) - the 'wolves' (vṛkāḥ) (metaphorical for vices) (wolves)

(noun)

Nominative, masculine, plural of vṛka

vṛka - wolf; an evil or rapacious person; vice (metaphorical)

भयङ्कराः (bhayaṅkarāḥ) - terrifying (terrifying; fearful; causing fear)

(adjective)

Nominative, masculine, plural of bhayaṅkara

bhayaṅkara - terrifying; fearful; causing fear; dreadful

Compound type : Tatpurusha (bhaya+kara)

• bhaya – fear; dread; terror
  noun (neuter)
• kara – making; causing; performing
  adjective
  Agent Noun / Adjective from √kṛ
  Root: √kṛ (class 8)

Note: Qualifies 'vṛkāḥ'

मनुष्यदेहगोचराः (manuṣyadehagocarāḥ) - which prey on the human body (which move in the human body; whose domain is the human body; preying on the human body)

(adjective)

Nominative, masculine, plural of manuṣyadehagocara

manuṣyadehagocara - whose sphere of activity is the human body; relating to the human body; preying on the human body

Compound type : Tatpurusha / Bahuvrihi (manuṣyadeha+gocara)

• manuṣya – human; man
  noun (masculine)
• deha – body; physical form
  noun (masculine)
• gocara – sphere of activity; range; object of sense; accessible to
  noun (masculine)

Note: Qualifies 'vṛkāḥ'

अभिद्रवन्ति (abhidravanti) - attack (they attack; they rush towards; they assail)

(verb)

3rd person , plural, active, present (lat) of abhidru

Prefix: abhi

Root: √dru (class 1)

सर्वतः (sarvataḥ) - from all sides (from all sides; everywhere; completely)

(indeclinable)

यतस्व (yatasva) - strive (strive; endeavor; exert yourself)

(verb)

2nd person , singular, middle, imperative (lot) of yat

Root: √yat (class 1)

पुण्यशीलने (puṇyaśīlane) - in the practice of virtue (in the practice of virtue; in the cultivation of merit)

(noun)

Locative, neuter, singular of puṇyaśīlana

puṇyaśīlana - practice of virtue; cultivation of merit; virtuous conduct

Compound type : Tatpurusha (puṇya+śīlana)

• puṇya – virtue; merit; righteous act; good deed
  noun (neuter)
• śīlana – practice; cultivation; habituation; observance
  noun (neuter)
  Root: √śīl (class 10)