Manava Dharmashastra 3.48

3.48

tāsu daśasu yā yugmā rātrayaḥ ṣaṣṭhyaṣṭamī daśamī dvādaśī caturdaśī ṣoḍaśī tāspagacchataḥ putrā jāyante |
ayugmāsu striyo duhitaraḥ |
tasmātputrotpattisiddhārthaṃ yugmāsu saṃviśedbhajeta maithunadharmeṇa striyamārtave | anuvādo'yam | ayamapi niyama eva—anutpannaputrasyāyugmāsvagamanam |

On the even days male children are conceived, and female ones on the uneven days; therefore one who desires a son should have recourse to ones wife on the even days of her “season.”—(48)

Medhātithi’s commentary (manubhāṣya):
Among the said ten days, the ‘even days’ are the sixth, the eighth, the tenth, the twelfth, the fourteenth and the sixteenth; and when one has intercourse with one’s wife on these days, sons are born to him.

‘One who desires a son should have recourse to one’s wife on the even days of her season;’—i.e., because ‘female ones’—i.e., daughters are conceived—‘on the uneven days,’—‘therefore’ for the bringing about of the birth of sons, ‘one should have recourse to’—have sexual intercourse with—‘one’s wife, on the even days of her season?’

This is a mere reiteration; and it is also a restrictive rule, the meaning being that ‘one, for whom no sons have been born, should not have intercourse with one’s wife on the uneven days.’—(48)

This verse is quoted in Parāśaramādhava (Ācāra, p. 438), where ‘yugmāsu’ is explained as ‘even nights’, and ‘samvishet’ as ‘should approach’;—in Vīramitrodaya (Āhnika, p. 559), which explains ‘ayugmāsu’ as ‘odd nights’, and ‘samvishet’ as ‘should approach;—also in Vīramitrodaya (Saṃskāra p. 153) in support of the view that ‘one who desires a son should approach his wife on the even nights of the period, and he who desires a daughter, on the odd nights’; and adds that though the text speaks simply of ‘nights’, yet the act should be done after midnight; and also that the special mention of the ‘night’ clearly indicates that intercourse during the day is forbidden.

Smṛtitattva quotes this verse as describing the results accruing from approaching one’s wife on certain days.

This is quoted in Aparārka (p. 103);—in Hemādri (Kāla, p. 722);—in Saṃskāramayūkha (p. 16);—in Smṛticandrikā (Saṃskāra, p. 37);—in Saṃskāraratnamālā (p. 680);—and in Nṛsiṃhaprasāda (Saṃskāra, p. 24 b).

Comparative notes by various authors
(verses 3.45-50)
See Comparative notes for Verse 3.45.