महाभारतः mahābhārataḥ - book-3, chapter-82, verse-82

तत्र संध्यामुपासीत ब्राह्मणः संशितव्रतः ।
उपास्ता च भवेत्संध्या तेन द्वादशवार्षिकी ॥८२॥

82. tatra saṁdhyāmupāsīta brāhmaṇaḥ saṁśitavrataḥ ,
upāstā ca bhavetsaṁdhyā tena dvādaśavārṣikī.

82. tatra sandhyām upāsīta brāhmaṇaḥ saṃśitavrataḥ
upāstā ca bhavet sandhyā tena dvādaśavārṣikī

82. There, a Brahmin who is resolute in his vows should perform the twilight worship (sandhyā). By his performance, that (single) act of sandhyā will be equivalent to one performed for twelve years.

Words meanings summery:

• तत्र (tatra) - there, in that place

• सन्ध्याम् (sandhyām) - twilight worship (sandhyā) (twilight worship, evening prayer)

• उपासीत (upāsīta) - should worship, should attend, should perform

• ब्राह्मणः (brāhmaṇaḥ) - a Brahmin, a member of the priestly class

• संशितव्रतः (saṁśitavrataḥ) - firm in vows, resolute in observances

• उपास्ता (upāstā) - worshipped, performed

• च (ca) - and, also

• भवेत् (bhavet) - would be, should be

• सन्ध्या (sandhyā) - twilight worship (sandhyā) (twilight worship, evening prayer)

• तेन (tena) - by him, by that

• द्वादशवार्षिकी (dvādaśavārṣikī) - lasting twelve years, twelve-yearly

Words meanings and morphology

तत्र (tatra) - there, in that place

(indeclinable)

Locative case of 'tad' in form of an adverb

सन्ध्याम् (sandhyām) - twilight worship (sandhyā) (twilight worship, evening prayer)

(noun)

Accusative, feminine, singular of sandhyā

sandhyā - twilight; junction of day and night; daily prayer at sunrise, noon, and sunset

Prefix: sam

Root: dhā (class 3)

उपासीत (upāsīta) - should worship, should attend, should perform

(verb)

3rd person , singular, middle, optative (vidhi liṅ) of upa-ās

Prefix: upa

Root: ās (class 2)

ब्राह्मणः (brāhmaṇaḥ) - a Brahmin, a member of the priestly class

(noun)

Nominative, masculine, singular of brāhmaṇa

brāhmaṇa - a Brahmin; relating to brahman

संशितव्रतः (saṁśitavrataḥ) - firm in vows, resolute in observances

(adjective)

Nominative, masculine, singular of saṃśitavrata

saṁśitavrata - one whose vows are sharpened, firm in vows, resolute

Compound type : bahuvrihi (saṃśita+vrata)

• saṃśita – sharpened, firm, resolute
  adjective (masculine)
  Past Passive Participle
  From root śo, 'to sharpen', with prefix sam.
  Prefix: sam
  Root: śo (class 4)
• vrata – vow, sacred observance, religious duty
  noun (neuter)

उपास्ता (upāstā) - worshipped, performed

(adjective)

Nominative, feminine, singular of upāsta

upāsta - worshipped, attended, performed

Past Passive Participle

From root ās, with prefix upa.

Prefix: upa

Root: ās (class 2)

च (ca) - and, also

(indeclinable)

भवेत् (bhavet) - would be, should be

(verb)

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

Root: bhū (class 1)

सन्ध्या (sandhyā) - twilight worship (sandhyā) (twilight worship, evening prayer)

(noun)

Nominative, feminine, singular of sandhyā

sandhyā - twilight; junction of day and night; daily prayer at sunrise, noon, and sunset

Prefix: sam

Root: dhā (class 3)

तेन (tena) - by him, by that

(pronoun)

Instrumental, masculine, singular of tad

tad - that, he, she, it

द्वादशवार्षिकी (dvādaśavārṣikī) - lasting twelve years, twelve-yearly

(adjective)

Nominative, feminine, singular of dvādaśavārṣika

dvādaśavārṣika - twelve-yearly, lasting twelve years

From dvādaśa (twelve) + varṣa (year) + ika (suffix)

Compound type : tatpurusha (dvādaśa+varṣa)

• dvādaśa – twelve
  numeral (neuter)
• varṣa – year, rain
  noun (neuter)