Manava Dharmashastra 2.7

2.7

yadukaṃ vedavitsambandhena smṛteḥ prāmāṇyaṃ tadanena prakaṭayati | yaḥ kaściddharmo varṇadharma āśramadharmaḥ saṃskāradharmaḥ sāmānyarūpo viśeṣarūpaśca kasyacidbrāhmaṇādervarṇasya | manunā parikīrtitaḥ | sa sarvo'pi vede'bhihitaḥ pratipāditaḥ | yathā caitattathā pūrvaśloka uktam | sarvajñānamayo hi saḥ | sarveṣāṃ jñānānāmadṛṣṭaviṣayāṇāṃ heturnimittaṃ vedaḥ | sarvairjñānairnirmita iveti jñāne tadvikāratvamadhyāropya mayaṭ kṛtaḥ | yo hi yadvikāraḥ sa tanmayastatsvabhāva ityucyate | vedaśca jñānahetutvāttanmaya iti | satkāryadarśane kāraṇaṃ kāryasvabhāvamiti | athavā sarvajñānāddhetoḥ āgataḥ 'hetumanuṣyebhya' (pā. sū. 4-3-81) iti mayaṭ kriyate |

Medhātithi’s commentary (manubhāṣya):
This verse proceeds to make it clear how the authority of the Smṛti (Recollection) is due to its connection with persons knowing the Veda.

‘Whatever Dharma’—duties relating to castes, duties relating to life-stages, duties relating to sacramental rites, in their general or special forms—‘for whatever person’—for the Brāhmaṇa or other castes—‘has been described by Manu’—‘all this is declared in the Veda’—i.e., is expounded in it; how this is done has been shown in the preceding verse.

‘Since the Veda embodies all knowledge’;—Veda is the cause, the source, of all that is worth knowing, in regard to superphysical things. The affix ‘mayaṭ’ has been added in the sense that the Veda is made up of all knowledge; applying to ‘knowledge’ the character of being the product of the Veda. When one thing is the produot of another, the latter is spoken of as ‘embodying’ the former, i.e., of the same nature as the other; and Veda, being the source of knowledge, is said to ‘embody’ it. According to the Sāṅkhya theory of the Product being always existent in the Cause, the Cause is of the same nature as the Product.

Or, the meaning may be that ‘the Veda proceeds from all knowledge’ as its source; the ‘mayaṭ’ affix in this sense being used according to Pāṇini’s Sūtra 4.3.81.—(7)