महाभारतः mahābhārataḥ - book-13, chapter-107, verse-18

ऋषयो दीर्घसंध्यत्वाद्दीर्घमायुरवाप्नुवन् ।
तस्मात्तिष्ठेत्सदा पूर्वां पश्चिमां चैव वाग्यतः ॥१८॥

18. ṛṣayo dīrghasaṁdhyatvāddīrghamāyuravāpnuvan ,
tasmāttiṣṭhetsadā pūrvāṁ paścimāṁ caiva vāgyataḥ.

18. ṛṣayaḥ dīrghasandhyatvāt dīrgham āyuḥ avāpnuvan
tasmāt tiṣṭhet sadā pūrvām paścimām ca eva vāgyataḥ

18. Sages (ṛṣi) attained long life due to their prolonged observance of the twilight ritual (sandhyā). Therefore, one should always remain, controlling one's speech, for both the morning and evening twilight rituals.

Words meanings summery:

• ऋषयः (ṛṣayaḥ) - sages (ṛṣi) (sages, seers)

• दीर्घसन्ध्यत्वात् (dīrghasandhyatvāt) - due to their prolonged observance of the twilight ritual (because of long observance of twilight rituals)

• दीर्घम् (dīrgham) - long

• आयुः (āyuḥ) - life (life, duration of life)

• अवाप्नुवन् (avāpnuvan) - attained (they obtained, reached)

• तस्मात् (tasmāt) - therefore (therefore, from that)

• तिष्ठेत् (tiṣṭhet) - one should remain (observing the ritual) (one should stand, remain, exist)

• सदा (sadā) - always (always, ever)

• पूर्वाम् (pūrvām) - the morning (twilight ritual) (former, eastern, prior)

• पश्चिमाम् (paścimām) - the evening (twilight ritual) (western, later, last)

• च (ca) - and (and, also)

• एव (eva) - indeed (only, just, indeed, very)

• वाग्यतः (vāgyataḥ) - controlling one's speech (restrained in speech, silent)

Words meanings and morphology

ऋषयः (ṛṣayaḥ) - sages (ṛṣi) (sages, seers)

(noun)

Nominative, masculine, plural of ṛṣi

ṛṣi - sage, seer, inspired poet, a Vedic priest

Root: ṛṣ

दीर्घसन्ध्यत्वात् (dīrghasandhyatvāt) - due to their prolonged observance of the twilight ritual (because of long observance of twilight rituals)

(noun)

Ablative, neuter, singular of dīrghasandhyatva

dīrghasandhyatva - the state of observing sandhyā for a long time

Compound of dīrgha and sandhyatva

Compound type : tatpuruṣa (dīrgha+sandhyatva)

• dīrgha – long, tall, deep
  adjective (masculine)
• sandhyatva – the state or condition of observing sandhyā
  noun (neuter)
  from sandhyā + -tva (abstract suffix)

दीर्घम् (dīrgham) - long

(adjective)

Accusative, neuter, singular of dīrgha

dīrgha - long, tall, deep, extensive

Note: Modifies āyuḥ

आयुः (āyuḥ) - life (life, duration of life)

(noun)

Accusative, neuter, singular of āyus

āyus - life, duration of life, vital power, food

Root: ī

अवाप्नुवन् (avāpnuvan) - attained (they obtained, reached)

(verb)

3rd person , plural, active, past imperfect (laṅ) of avāp

imperfect, 3rd person plural, active voice

from root āp (to obtain) with prefix ava

Prefix: ava

Root: āp (class 5)

तस्मात् (tasmāt) - therefore (therefore, from that)

(indeclinable)

तिष्ठेत् (tiṣṭhet) - one should remain (observing the ritual) (one should stand, remain, exist)

(verb)

3rd person , singular, active, optative (vidhi liṅ) of sthā

optative, 3rd person singular, active voice

from root sthā (class 1, parasmaipada)

Root: sthā (class 1)

सदा (sadā) - always (always, ever)

(indeclinable)

पूर्वाम् (pūrvām) - the morning (twilight ritual) (former, eastern, prior)

(adjective)

Accusative, feminine, singular of pūrvā

pūrvā - eastern, former, prior, first, morning (feminine often refers to sandhyā)

पश्चिमाम् (paścimām) - the evening (twilight ritual) (western, later, last)

(adjective)

Accusative, feminine, singular of paścimā

paścimā - western, later, last, evening (feminine often refers to sandhyā)

च (ca) - and (and, also)

(indeclinable)

एव (eva) - indeed (only, just, indeed, very)

(indeclinable)

वाग्यतः (vāgyataḥ) - controlling one's speech (restrained in speech, silent)

(adjective)

Nominative, masculine, singular of vāgyata

vāgyata - restrained in speech, silent, ascetic

Compound of vāc (speech) and yata (restrained)

Compound type : tatpuruṣa (vāc+yata)

• vāc – speech, voice, word
  noun (feminine)
  Root: vac (class 2)
• yata – restrained, controlled, disciplined
  adjective (masculine)
  Past Passive Participle
  from root yam (to restrain)
  Root: yam (class 1)