महाभारतः mahābhārataḥ - book-7, chapter-56, verse-20

अक्षौहिण्यो हि ताः सर्वा रक्षिष्यन्ति जयद्रथम् ।
द्रोणश्च सह पुत्रेण सर्वास्त्रविधिपारगः ॥२०॥

20. akṣauhiṇyo hi tāḥ sarvā rakṣiṣyanti jayadratham ,
droṇaśca saha putreṇa sarvāstravidhipāragaḥ.

20. akṣauhiṇyaḥ hi tāḥ sarvāḥ rakṣiṣyanti jayadratham
droṇaḥ ca saha putreṇa sarvāstravidhipāragaḥ

20. hi tāḥ sarvāḥ akṣauhiṇyaḥ jayadratham rakṣiṣyanti
droṇaḥ ca putreṇa saha sarvāstravidhipāragaḥ

20. Indeed, all those akṣauhiṇī divisions will protect Jayadratha. And Drona, along with his son, being a master of all weapon-arts, will also protect him.

Words meanings summery:

• अक्षौहिण्यः (akṣauhiṇyaḥ) - military divisions (akṣauhiṇīs)

• हि (hi) - indeed, surely, for

• ताः (tāḥ) - those

• सर्वाः (sarvāḥ) - all

• रक्षिष्यन्ति (rakṣiṣyanti) - will protect

• जयद्रथम् (jayadratham) - Jayadratha

• द्रोणः (droṇaḥ) - Drona

• च (ca) - and

• सह (saha) - with, together with

• पुत्रेण (putreṇa) - along with his son (by the son, with the son)

• सर्वास्त्रविधिपारगः (sarvāstravidhipāragaḥ) - master of all weapon-arts

Words meanings and morphology

अक्षौहिण्यः (akṣauhiṇyaḥ) - military divisions (akṣauhiṇīs)

(noun)

Nominative, feminine, plural of akṣauhiṇī

akṣauhiṇī - a large ancient Indian army division, typically consisting of 21,870 chariots, 21,870 elephants, 65,610 horses, and 109,350 foot soldiers

हि (hi) - indeed, surely, for

(indeclinable)

ताः (tāḥ) - those

(pronoun)

Nominative, feminine, plural of tad

tad - that, he, she, it

सर्वाः (sarvāḥ) - all

(pronoun)

Nominative, feminine, plural of sarva

sarva - all, every, whole

रक्षिष्यन्ति (rakṣiṣyanti) - will protect

(verb)

3rd person , plural, active, future (lṛṭ) of rakṣ

Root: rakṣ (class 1)

जयद्रथम् (jayadratham) - Jayadratha

(proper noun)

Accusative, masculine, singular of jayadratha

jayadratha - Jayadratha (name of the king of Sindhu)

द्रोणः (droṇaḥ) - Drona

(proper noun)

Nominative, masculine, singular of droṇa

droṇa - Drona (name of the preceptor of the Kauravas and Pandavas)

च (ca) - and

(indeclinable)

सह (saha) - with, together with

(indeclinable)

Note: Governs instrumental case.

पुत्रेण (putreṇa) - along with his son (by the son, with the son)

(noun)

Instrumental, masculine, singular of putra

putra - son

Note: Refers to Aśvatthāman, Drona's son.

सर्वास्त्रविधिपारगः (sarvāstravidhipāragaḥ) - master of all weapon-arts

(adjective)

Nominative, masculine, singular of sarvāstravidhipāraga

sarvāstravidhipāraga - one who has crossed beyond the knowledge of all weapons, master of all weapon-arts

Compound type : tatpurusha (sarva+astra+vidhi+pāraga)

• sarva – all, every
  pronoun (masculine)
• astra – missile, weapon
  noun (neuter)
  Root: as (class 4)
• vidhi – rule, method, rite, art
  noun (masculine)
  Prefix: vi
  Root: dhā (class 3)
• pāraga – one who has reached the other side, master, expert
  adjective (masculine)
  Prefix: pāra
  Root: gā (class 1)

Note: Qualifies Drona.