Manava Dharmashastra 1.69

1.69

prakṛtatvāddaivivāni varṣāṇi parigṛhyante | tathā ca purāṇakāraḥ "ityetadṛṣibhirgītaṃ divyayā saṅkhyayā dvijāḥ || divyenaiva pramāṇena yugasaṅkhyā prakīrtitā" | tāni catvāri sahasrāṇi kṛtayugaṃ nāma kālaḥ | tasya kṛtayugasya tāvantyeva śatāni, catvāri, sandhyā | sandhyāṃśastasya tathā vidhaḥ tatparimāṇāścatvārivarṣaśatānītyarthaḥ | yatrātītasya kālasyāgāminaśca svabhāvānuvṛttiḥ sā sandhyā | ubhayakāladharmānuvidhānaṃ sandhyāṃśaḥ, yatreṣatpūrvadharmānuvṛttirbhūyasī bhāvino yugasya |

They say that four thousnd ‘years’ are what is the ‘Kṛta-cycle’; as many hundred ‘years’ form the ‘Juncture’ (Morning); and of equal measure is the ‘Juncture-end’ (Evening).—(69)

Medhātithi’s commentary (manubhāṣya):
The ‘years’ here spoken of are taken as the years of the Gods; as it is this that has been mentioned last. Says the Author of the Purāṇas—‘O Brāhmaṇas, all this has been described by the divine measure: the measure of the Time-Cycles has been described by the divine measure.’—‘Four thousand’ such ‘years’ of the Gods constitute the Time-Cycle known as ‘Kṛta’:—of the ‘Kṛta’ cycle, ‘as many’, i.e. four ‘hundred’ ‘years’ form the ‘Juncture’; and of the same ‘Kṛta’ Cycle, the ‘Juncture-end’ is consisting of a period of four hundred years. That period of time which partakes in equal degree of the character of the preceding as well as that of the succeeding Cycle, is called ‘Juncture’; and ‘Juncture-end’ is that period of time which also partakes of the character of both, but in a less degree, of the preceding and, to a greater degree, of the succeeding Cycle.

The text contains the word ‘tāvacchatī’; and it is necessary to And out the rule under which the final I has been lengthened. The only grammatical explanation of the word possible is that it should be expounded as ‘tāvat śatānām sa māhārah’, ‘the collection of as many hundreds’; the term ‘tāvat’, ending in the ‘vatu’ affix, becomes a numeral according to Pāṇini’s Sūtra 1.1.23, by which words ending in ‘vatu’ are regarded as ‘numerals’; so that the said compound having a numeral for its first number becomes a ‘Dvigu’, according to Pāṇini 2.1.25; and since the Feminine affix ṭāp is precluded from Dvigu compounds, we have the Feminine affix ṅīp; and the word ‘tāvat’ means ‘one whose measure is tat (that)’: it being derived from the pronoun ‘tat’ with the ‘vatup’ affix, added according to Pāṇini’s Sūtra 5.2.39; the vowel in ‘tat’ being lengthened by the sūtra 6.3.91. If the form ‘tāvātī’ were explained in any other way,—for instance, if it were taken as a Bahubrīhi compound, being expounded as ‘tāvanti śatāni yasyāḥ’,—then, since the word ‘śata’ ends in ‘a’, it would take the Feminine affix ‘ṭāp’ according to Pāṇini 4.1.1; so that the form would be ‘tāvaccatā.’ This is the meaning.—(69)