Manava Dharmashastra 3.112

3.112

vaiśvadevikādaikalpikācchāddhānnityamidaṃ śrāddhāntaramucyate |
candrakṣaye'māvāsyāyām | tatrāpi na yasyāṃ kasyāṃcana velāyāṃ kiṃ tarhi pitṛyajñaṃ nirvattyai | śrauto yaḥ piṇḍapitṛyajñastaṃ kṛtvā | evaṃ ca yastasya kālaḥ sa evāsyāpi labhyate | taduktamamāvāsyāyāmaparāhṇe piṇḍapitṛyajña iti |
anāhitāgnerapyaupāsanayogo'styeva | tathā cāha | 'evamanāhitāgnirnitye śrapayitve'tyādi | agnimān vaivāhikenāgninā tadvān, dāyakālāhṛtena vā |
vipragrahaṇamavivakṣitam | kṣatriyavaiśyayorapīṣyate | evaṃ smṛtyantareṣu hyaviśeṣeṇoktam |
piṇḍānvāhāryakamiti | nāmadheyamidamasya śrāddhasya | piṇḍānāmanu paścāddhāhiyate'nuṣṭhīyate | tat 'piṇḍānvāhāryakaṃ' bhavati |
māsaścānumāsaśca, tayorbhavaṃ māsānumāsikam | māsānumāsaśabdasamudāyo māsagatāṃ vīpsāmānaṣṭe | māsi māsi kartavyamityuktaṃ bhavati | ataśca nityatvāsaddhiḥ | yadyapyanumāsaśabdādvīpsāvagatirbhavati, māsaśabdo'tiricyate, tathāpi padyagranthe gauravaṃ nādriyate |
śrāddhamityetadapi nāmaiva | kuryāditi vidhiḥ |

Month after Month, on the moonless day, the Brāhmaṇa with the Fire shall, after having performed the Pitṛyajña, offer the “Piṇḍānvāhāryaka.”—(122)

Medhātithi’s commentary (manubhāṣya):
The śrāddha described here is the compulsory one, as distinct from the Vaiśvadeva-śrāddha, which is optional.

‘On the moon-leas day’— on the Amāvāsya day. There also not at any and every time, but only ‘after having performed the Pitṛyajña.’ That is, after having performed that Ptṛyajña which has been prescribed in the Śruti. Thus the time for the Śrāddha in question comes to be the same as that for this latter; and in connection with this it has been laid down that the Piṇḍapitṛyajña is to be performed on the Amāvāsya day, in the afternoon.’

Even for one who has not set up the fire, the performance of such offerings is essential; as it is declared—‘the person who has not set up the fire having made the accessary offerings &c.’

‘The Brāhmaṇa with the fire’—i.e., he who is keeping up the marriage-fire, or who has set up the fire since succession to his property. No significance is meant to be attached to the mention of the ‘Brāhmaṇa,’ since the śrāddha in question is meant to be performed by the Kṣatriya and the Vaiśya also; hence it is that other smṛtis have prescribed this śrāddha without special reference to any particular caste.

‘Piṇḍānvāhārya kam;’—this is the proper name of this śrāddha; the etymological explanation is that ‘that which is offered along with balls of food, Piṇḍas, is piṇḍānvāhāryaka.’