तृतीयं ब्राह्मणम् (ज्येष्ठब्राह्मणं वा प्राणविद्याब्राह्मणम्) स यः कामयेत महत्प्राप्नुयामित्युदगयन आपूर्यमाणपक्षस्य पुण्याहे द्वादशाहमुपसद्व्रती भूत्वौदुम्बरे कंसे चमसे वा सर्वौषधं फलानीति संभृत्य परिसमुह्य परिलिप्याग्निमुपसमाधाय परिस्तीर्यावृताज्यं संस्कृत्य पुंसा नक्षत्रेण मन्थं संनीय जुहोति यावन्तो देवास्त्वयि जातवेदस्तिर्यञ्चो घ्नन्ति पुरुषस्य कामान् ।तेभ्योऽहं भागधेयं जुहोमि ते मा तृप्ताः सर्वैः कामैस्तर्पयन्तु स्वाहा ।या तिरश्ची निपद्यसेऽहं विधरणी इति ।तां त्वा घृतस्य धारया यजे संराधनीमहं स्वाहा ॥बृह. ६,३.१ ॥
In plain words
He who desires to attain greatness should, on an auspicious day in the northward course of the sun, in the bright fortnight, having kept the preliminary vow for twelve days, gather in a bowl or cup of fig-wood all kinds of herbs and fruits, sweep and smear the place, lay the fire, strew the grass about, prepare the melted butter in due order, and mix the mash under a male constellation. Then he offers, saying: "However many gods there are in thee, O knower of all born things, who crosswise slay the desires of a man — to them I offer their portion; may they, satisfied, satisfy me with all desires. Svāhā. To thee who liest crosswise, thinking, 'I am the withholder' — thee I worship with a stream of melted butter, as the giver of fulfilment. Svāhā."
The commentators
Bṛhadāraṇyakopaniṣadbhāṣyam· Leaf 10.116· bhāṣya
ख्यं कर्म आरभ्यते महत्त्वप्राप्तये ; महत्त्वे च सति अर्थसिद्धं हि वित्तम् । तदुच्यते—स यः कामयेत, स यो वित्तार्थी क- र्मण्यधिकृतः यः कामयेत ; किम् ? महन् महत्त्वम् प्राप्नु- याम् , महान्स्यामितीत्यर्थः । तत्र मन्थकर्मणो विधित्सितस्य कालोऽभिधीयते— उदगयने आदित्यस्य ; तत्र सर्वत्र प्राप्तौ आपूर्यमाणपक्षस्य शुक्लपक्षस्य ; तत्रापि सर्वत्र प्राप्तौ, पुण्याहे अनुकूले आत्मनः कर्मसिद्धिकर इत्यर्थः ; द्वादशाहम् , य- स्मिन्पुण्येऽनुकूले कर्म चिकीर्षति ततः प्राक् पुण्याहमेवा- रभ्य द्वादशाहम् , उपसद्व्रती, उपसत्सु व्रतम् , उपसदः प्रसिद्धा ज्योतिष्टोमे, तत्र च स्तनोपचयापचयद्वारेण प- योभक्षणं तद्व्रतम् ; अत्र च तत्कर्मानुपसंहारात् केव- लमितिकर्तव्यताशून्यं पयोभक्षणमात्रमुपादीयते ; ननु उप- सदो व्रतमिति यदा विग्रहः, तदा सर्वमितिकर्तव्यतारूपं ग्राह्यं भवति, तत् कस्मात् न परिगृह्यत इत्युच्यते— स्मा- र्तत्वात्कर्मणः ; स्मार्तं हीदं मन्थकर्म । ननु श्रुतिविहितं सत् कथं स्मार्तं भवितुमर्हति— स्मृत्यनुवादिनी हि श्रुति- रियम् ; श्रौतत्वे हि प्रकृतिविकारभावः ; ततश्च प्राकृतधर्म- ग्राहित्वं विकारकर्मणः ; न तु इह श्रौतत्वम् ; अत एव च आवसथ्याग्नौ एतत्कर्म विधीयते, सर्वा च आवृत् स्मार्तैवेति ।
In plain words
This rite — named just before — exists to make a man great, and only once he is great does his wealth actually mean anything. Scripture puts it plainly: whoever wants wealth, and is entitled to perform this rite, may desire — desire what? To attain greatness, to become great, that's the whole of it. As for when: during the sun's course to the north, in the waxing half of the month, on a day judged auspicious and favorable to his own success. Twelve days, counting back from that chosen day, he keeps the upasad-vow — the same vow known from the upasads of the great Jyotiṣṭoma sacrifice, where milking is carefully increased and then decreased, and drinking that milk is the whole of the vow. But here he takes only that one piece — plain milk-drinking, with none of the surrounding ritual detail — because the rest of that older rite was never meant to come along with it. Someone might object: read the compound the other way, as 'the vow belonging to the upasad,' and surely all its detail should transfer too — so why doesn't it? Because this rite rests on remembered tradition, not on direct scriptural injunction — that's the answer. But then comes the sharper question: how can something scripture itself describes fail to count as scriptural? Because this particular passage isn't laying down something new — it's simply repeating what tradition already held. Had it been a fresh Vedic injunction, the rite would stand in that strict archetype-and-copy relationship, obligated to inherit every feature of its model. That relationship simply doesn't hold here. Which is exactly why this rite belongs to the ordinary household fire, and its whole procedure is, start to finish, drawn from tradition rather than direct revelation.
Close to the Sanskrit
The rite called [mantha] is undertaken for the attainment of greatness; and when there is greatness, wealth indeed becomes fulfilled in its purpose. This is what is stated: 'whoever might desire' — that is, whoever, desirous of wealth and qualified for the rite, might desire; desire what? 'May I attain greatness' — that is, 'may I become great,' this is the meaning. There, the time for the mantha-rite one intends to perform is declared: in the northward course of the sun; there, in the general case, in the waxing fortnight, that is, the bright fortnight; there too, in the general case, on an auspicious day — favorable, that is, productive of the success of the rite for oneself — this is the meaning. 'The twelve-day period': on which auspicious, favorable day he wishes to perform the rite, counting back from that, beginning exactly with that auspicious day, twelve days. 'One who observes the upasad-vow' — the vow observed during the upasads, the upasads being well known in the Jyotiṣṭoma sacrifice; there, by means of increasing and decreasing the milking of the udder, the drinking of milk alone is that vow. But here, since that entire rite is not carried over, only the mere drinking of milk, empty of any further procedural content, is adopted. Objection: when the compound is analyzed as 'the vow of the upasad,' then the whole of the procedural content should be taken — why, then, is it not adopted? This is explained: because the rite is smārta. For this mantha-rite is indeed smārta. Objection: but how can something enjoined by scripture be smārta? This scripture merely restates what is already in smṛti; for if it were śrauta, there would be an archetype-and-modification relationship, and the derivative rite would then have to take on all the properties of the archetype rite — but that status does not apply here. For this very reason, this rite is enjoined in the āvasathya fire, and the whole liturgical procedure is indeed simply smārta.
Bṛhadāraṇyakopaniṣadbhāṣyam· Leaf 10.117· bhāṣya
डपसद्व्रती भूत्वा पयोव्रती सन्नित्यर्थः औदुम्बरे उदुम्बरवृ- क्षमये, कंसे चमसे वा, तस्यैव विशेषणम्- कंसाकारे चम- साकरे वा औदुम्बर एव ; आकारे तु विकल्पः, न औदुम्बरत्वे । अत्र सर्वौषधं सर्वासामोषधीनां समूहं यथासंभवं यथाशक्ति च सर्वां ओषधीः समाहृत्य ; तत्र ग्राम्याणां तु दश निय- मेन ग्राह्या व्रीहियवाद्या वक्ष्यमाणाः ; अधिकग्रहणे तु न दोषः ; ग्राम्याणां फलानि च यथासंभवं यथाशक्ति च ; इतिशब्दः समस्तसंभारोपचयप्रदर्शनार्थः, अन्यदपि यत्सं- भरणीयं तत्सर्वं संभृत्येत्यर्थः ; क्रमस्तत्र गृह्योक्तो द्रष्ट- व्यः । परिसमूहनपरिलेपने भूमिसंस्कारः । अग्निमुपस- माधायेति वचनात् आवसथ्येऽग्नाविति गम्यते, एकवच्च- नात् उपसमाधानश्रवणाच्च ; विद्यमानस्यैव उपसमाधानम् ; परिस्तीर्य दर्भान् ; आवृता- स्मार्तत्वात्कर्मणः स्थालीपाका- वृत् परिगृह्यते- तया आज्यं संस्कृत्य ; पुंसा नक्षत्रेण पुंना- म्ना नक्षत्रेण पुण्याहसंयुक्तेन, मन्थं सर्वौषधफलपिष्टं तत्रौदु- म्बरे चमसे दधनि मधुनि घृते च उपसिच्य एकया उप- मन्थन्या उपसंमथ्य, संनीय मध्ये संस्थाप्य, औदुम्बरेण स्रुवेण आवापस्थाने आज्यस्य जुहोति एतैर्मन्त्रैः 'यावन्तो देवाः' इत्यादिः ॥
In plain words
Once he has kept the upasad-vow — meaning, lived on milk alone — that phrase is explained. The vessel itself must be udumbara wood, shaped either like a kaṃsa or a camasa; the choice is only ever in the shape, never in the wood. 'All herbs' means exactly that: gather every herb you can find, and as many as you're able to. Among the ordinary cultivated grains, though, ten are non-negotiable — rice, barley, and the rest already named — though there's no harm in bringing more. Gather the fruits of those same plants the same way, as far as you can and as much as you can. That closing 'and so on' simply means: whatever else belongs in this collection, gather that too. For the order of steps, look to the household ritual manual. Preparing the ground just means clearing it and smearing it. When the text says he tends the fire, it means the household fire already burning — you can tell from the singular, and from the very word used, which only applies to a fire already alight, never one being lit fresh. Spread the sacred grass. Since this rite rests on remembered tradition rather than revealed scripture, it simply borrows its procedure from the familiar cooking-pot offering, and prepares the ghee the same way. Under a lunar mansion with a masculine name, on a day judged auspicious, he pours the ground mixture of every herb and fruit into the udumbara cup, into curd, honey, and ghee, stirs it with one udumbara stick, gathers it into the center, and with the udumbara ladle offers the ghee at the proper point — reciting the mantras that begin, 'as many as are the gods...'
Close to the Sanskrit
Having become one committed to the upasad-vow, that is, being one whose vow is confined to milk — that is the meaning. [The vessel is] made of udumbara wood, whether a kaṃsa or a camasa; or else this is a qualifier of that very word: whether in the shape of a kaṃsa or in the shape of a camasa, it is made of udumbara wood alone; the option lies only in the shape, not in the material being udumbara. Here, 'all herbs' means having gathered together, as far as possible and to the extent of one's ability, a collection of all the herbs. Among the cultivated ones, however, ten must be taken by rule — rice, barley, and so on, as will be stated; there is no fault in taking more. And also the fruits of the cultivated plants, as far as possible and to the extent of one's ability. The word 'iti' serves to show the accumulation of the entire mass of materials; the meaning is that whatever else needs to be gathered, all of it should be gathered. The sequence there should be understood as stated in the Gṛhya-sūtra. Preparing the ground means clearing it and smearing it. From the statement 'having tended the fire,' it is understood that the āvasathya fire is meant, because of the singular number and because the word 'tending' is used — tending applies only to a fire that already exists. Having spread the darbha grass around — 'the recurring procedure': since this rite is smārta, the procedure of the sthālīpāka offering is adopted for it — having consecrated the ghee by that procedure. With a masculine-named lunar asterism, joined with an auspicious day — having poured the mantha, ground from all the herbs and fruits, there into the udumbara cup, into curd, honey, and ghee, having churned it with one stirring-stick, having gathered it and set it in the middle, with the udumbara ladle, at the place of pouring the ghee, he offers with these mantras beginning 'as many as are the gods.'