BhG 13.21

syntax

puruṣaḥ hi (indeed a person) prakṛti-sthaḥ (who stays in nature) prakṛti-jān guṇān (guṇas born fom nature) bhuṅkte (he eats).
asya [puruṣasya] (of this person) guṇa-saṅgaḥ (attachment to the guṇas) sad-asad-yoni-janmasu (of the births in good and evil wombs) kāraṇam [ucyate] (it is said a cause).

grammar

puruṣaḥ	–	puruṣa 1n.1 m. – a person (from: √pur – to precede, to lead or √pṝ – to fill, to nourish, puru – abundance, pūru – people);
prakṛti-sthaḥ	–	prakṛti-stha 1n.1 m.; yaḥ prakṛtau tiṣṭhati saḥ – who stays in nature (from: pra-√kṛ – to produce, prakṛti – nature, primary substance, original cause; √sthā – to stand, stha – suffix: being in);
hi	–	av. – because, just, indeed, surely;
bhuṅkte	–	√bhuj (to eat, to enjoy) Praes. Ā 1v.1 – he eats, he enjoys;
prakṛti-jān	–	prakṛti-ja 2n.3 m.; prakṛteḥ jātān iti – born from nature (from: pra-√kṛ – to produce, prakṛti – nature, primary substance, original cause; √jan – to be born, ja – suffix: born);
guṇān	–	guṇa 2n.3 m. – qualities, virtues, threads (from: √grah – to take);
kāraṇam	–	kāraṇa 1n.1 n. – cause, motive, principle, the means (from: √kṛ – to do, karaṇa – deed, direct cause, instrument, helper);
guṇa-saṅgaḥ	–	guṇa-saṅga 1n.1 m.; TP: guṇaiḥ saṅga iti – attachment to the guṇas (from: √grah – to take, guṇa – quality, virtue, thread; sam-√gam – come together or √sañj – to attach, to stick, to embrace, saṅga – clinging, contact, relation, desire, attachment);
asya	–	idam sn. 6n.1 n. – of this;
sad-asad-yoni-janmasu	–	sad-asad-yoni-janman 7n.3 m.; TP: yāni janmāni satīṣu [devādi-]yoniṣv asatīṣu [tiryagādi-]yoniṣu santi teṣu – in such births, which are from the wombs of the good [beginning from divinitites] and from the wombs of the evil [beginning from animals] (from: √as – to be, sant – being, existing, true, the essence; a-sant – untrue, non-existing; yoni – womb, source, origin; √jan – to be born, janman – birth);

textual variants

hi → ‘pi (although);
puruṣaḥ prakṛti-stho hi → puruṣaḥ sukha-duḥkho hi (a person indeed has pleasure and distress);
guṇa-saṅgo ‘sya → guṇa-saṁgasya (of attachment to the guṇas);

Śāṃkara

yat puruṣasya sukha-duḥkhānāṃ bhoktṛtvaṃ saṃsāritvam ity uktaṃ tasya tat kiṃ-nimittam ity ucyate—
puruṣo bhoktā prakṛti-sthaḥ | prakṛtāv avidyā-lakṣaṇāyāṃ kārya-karaṇa-rūpeṇa pariṇatāyāṃ sthitaḥ prakṛti-sthaḥ | prakṛtim ātmatvena gataḥ ity etat | hi yasmāt | tasmād bhuṅkte upalabhata ity arthaḥ | prakṛtijān prakṛtito jātān sukha-duḥkha-mohākārābhivyaktān guṇān sukhī, duḥkhī, mūḍhaḥ, paṇḍito’ham ity evam | satyām apy avidyāyāṃ sukha-duḥkha-moheṣu guṇeṣu bhujyamāneṣu yaḥ saṅga ātma-bhāvaḥ saṃsārasya sa pradhānaṃ kāraṇaṃ yasya puruṣasya janmanaḥ | sa yathā-kāmo bhavati tat kratur bhavati [bhāvātmauttaṃ 4.4.5] ity ādi śruteḥ | tad etad āha—kāraṇaṃ hetur guṇa-saṅgo guṇeṣu saṅgo’sya puruṣasya bhoktuḥ sad-asad-yoni-janmasu | satyaś cāsatyaś ca yonayaḥ sad-asad-yonayas tāsu sad-asad-yonuṣu janmāni sad-asad-yoni-janmāni, teṣu sad-asad-yoni-janmaṣu viṣaya-bhūteṣu kāraṇaṃ guṇa-saṅgaḥ | athavā, sad-asad-yoni-janmasu asya saṃsārasya kāraṇaṃ guṇa-saṅga iti saṃsāra-pada-madhyāhāryam | sad-yonayo devādi-yonayaḥ | asad-yonayaḥ paśvādi-yonayaḥ | sāmarthyāt sad-asad-yonayaḥ manuṣya-yonayo’py aviruddhāḥ draṣṭāvyāḥ ||
etad uktaṃ bhavati—prakṛti-sthatvākhyāvidyā guṇeṣu ca saṅgaḥ kāmaḥ saṃsārasya kāraṇam iti | tac ca parivarjanāya ucyate | asya ca nivṛtti-kāraṇaṃ jñāna-vairāgye sa-saṃnyāse gītā-śāstre prasiddham | tac ca jñānaṃ purastād upanyastaṃ kṣetra-kṣetrajña-viṣayaṃ yaj jñātvāmṛtam aśnute [gītā 12.13] iti | uktaṃ cānyāpohenātad-dharmādhyāropeṇa ca

Rāmānuja

evam anyonyasaṃsṛṣṭayoḥ prakṛtipuruṣayoḥ kāryabheda uktaḥ; puruṣasya svatas svānubhavaikasukhasyāpi vaiṣayikasukhaduḥkhopabhogahetum āha
guṇaśabdaḥ svakāryeṣv aupacārikaḥ / svatas svānubhavaikasukhaḥ puruṣaḥ prakṛtisthaḥ prakṛtisaṃsṛṣṭaḥ, prakṛtijān guṇān prakṛtisaṃsargopādhikān sattvādiguṇakāryabhūtān sukhaduḥkhādīn, bhuṅkte anubhavati / prakṛtisaṃsargahetum āha
pūrvapūrvaprakṛtipariṇāmarūpadevamanuṣyādiyoniviśeṣeṣu sthito ‚yaṃ puruṣas tattadyoniprayuktasattvādiguṇamayeṣu sukhaduḥkhādiṣu saktaḥ tatsādhanabhūteṣu puṇyapāpakarmasu pravartate; tatas tatpuṇyapāpaphalānubhavāya sadasadyoniṣu sādhvasādhuṣu yoniṣu jāyate; tataś ca karmārabhate; tato jāyate; yāvad amānitvādikān ātmaprāptisādhanabhūtān guṇān sevate, tāvad eva saṃsarati / tad idam uktaṃ kāraṇaṃ guṇasaṅgo ‚sya sadasadyonijanmasu iti

Śrīdhara

tathāpy avikāriṇo janma-rahitasya ca bhoktṛtvaṃ katham iti | ata āha puruṣa iti | hi yasmāt | prakṛti-sthas tat-kārye dehe tādātmyena sthitaḥ puruṣaḥ | atas taj-janitān sukha-duḥkhādīn bhuṅkte | asya ca puruṣasya satīṣu devādi-yoniṣu asatīṣu tiryag-ādi-yoniṣu yāni janmāni teṣu guṇa-saṅgo guṇaiḥ śubhāśubha-karma-kāribhir indriyaiḥ saṅgaḥ kāraṇam ity arthaḥ

Madhusūdana

yat puruṣasya sukha-duḥkha-bhoktṛtvaṃ tādātmyenopagataḥ prakṛti-stho hy eva puruṣo bhuṅkte upalabhate prakṛti-jān guṇān | ataḥ prakṛti-ja-guṇopalambha-hetuṣu sad-asad-yoni-janmasu sad-yonayo devādyās teṣu hi sāttvikam iṣataṃ phalaṃ bhujyate | asad-yonayaḥ paśv-ādyās teṣu hi tāmasam aniṣṭaṃ phalaṃ bhujyate | atas tan nāsya puruṣasya guṇa-saṅgaḥ sattva-rajas-tamo-guṇātmaka-prakṛti-tādātmyābhimāna eva kāraṇam | na tv asaṅgasya tasya svataḥ saṃsāra ity arthaḥ | athavā guṇa-saṅgo guṇeṣu śabdādiṣu sukha-duḥkha-mohātmakeṣu saṅgo ‚bhilāṣaḥ kāma iti yāvat | sa evāsya sad-asad-yoni-janmasu kāraṇam sa yathā-kāmo bhavati tat kratur bhavati yat kratur bhavati tat karma kurute yat karma kurute tad abhisampadyate [BAU 4.4.5] iti śruteḥ | asminn api pakṣe mūla-kāraṇatvena prakṛti-tādātmyābhimāno draṣṭavyaḥ

Viśvanātha

kintu tatra anādy-avidyā-kṛtenādhyāsena eva karṭrva-bhoktṛtvādikaṃ tadīyam api dharmaṃ svīyaṃ manyate | tata evāsya saṃsāra ity āha puruṣa iti | prakṛtisthaḥ prakṛti-kārya-dehe tādātmyena hi sthitaḥ | prakṛtijān antaḥkaraṇa-dharmān śoka-moha-sukha-duḥkhādīn guṇān svīyān eva abhimanyamāno bhuṅkte | tatra kāraṇaṃ guṇa-saṅgaḥ | guṇamaya-deheṣu asyāsaṅgasyāpy ātmanaḥ saṅgo ‚vidyā-kalpitaḥ | kva bhuṅkte ity apekṣāyām āha satīṣu devādi-yoniṣu asatīṣu tiryag-ādi-yoniṣu śubhāśubha-karma-kṛtāsu yāni janmāni teṣu

Baladeva

prakṛty-adhiṣṭhāne sikhādibhoge ca puruṣasyaiva kartṛtvam ity etat sphuṭayati tasya prakṛti-saṃsarge hetuṃ ca darśayati puruṣa iti | cit-sukhaika-raso ‚pi puruṣo ‚nādikarma-vāsanayā prakṛtisthas tām adhiṣṭhita-tat-kṛta-dehendriyaḥ prāna-viśiṣṭaḥ sann eva tat-kṛtān guṇān sukhādīn bhuṅkte ‚nubhavati kvety āha sad iti | satīṣu deva-mānavādiṣv asatīṣu paśu-pakṣy-ādiṣu ca sādhv-asādhu-racitāsu yoniṣu yāni janmādīni teṣv iti tatra tatra puruṣasyaiva kartṛtvam |
tat-saṃsarge hetum āha kāraṇam iti | guṇo ‚saṅgo ‚nādi-guṇa-maya-visaya-spṛhā | ayam arthaḥ anādir jīvaḥ karma-rūpāṇādivāsanāraktaḥ | sa ca bhoktṛtvād bhogyān viṣayān spṛhayaṃs tad-arpita-kāmanādi-sannihitāṃ prakṛtim āśrayiṣyati yāvat sat-prasaṅgāt tat-tad-vāsanā kṣīyate | tat-kṣaye tu parātma-dhāma-sukhāni bhuṅkte so ‚śnute sarvān kāmān saha brahmaṇā vipaścitā ity ādi śrutibhya iti | yat tu prakṛter ity ādeḥ kārya-kāraṇety ādeḥ prakṛtyaiva cety āder nānyaṃ guṇebhyaḥ ity ādeś cāpātatārtha-grāhibhiḥ sāṅkhyaiḥ prakṛter eva kartṛtvam uktaṃ, tat kila rabhasābhidhānam eva loṣṭra-kāṣṭhavad acetanāyās tasyās tattva-sambhāvāt | upādānāparokṣa-cikīrṣākṛtimattvaṃ khalu kartṛtvaṃ, tac ca cetanasyaiveti śrutir āha – vijñānaṃ yajñaṃ tanute karmāṇi tanute ‚pi ca | eṣa hi draṣṭā spraṣṭā śrotā rasayitā ghrātā mantā boddhā kartā nijñānātmā puruṣaḥ ity ādikam |
yac ca puruṣa-sannidhānāc caitanyādhyāsāt tasyās tattvam ity āhus tan na | yat sannidhyadhasta-caitanyāt tasyāḥ kartṛtvaṃ tat tasyaiva sannihitasyeti suvacatvāt | na khalu tapāyaso dagdhṛtvam ayo-hetukam api tu vahni-hetukam eva dṛṣṭam | na ca calati jalaṃ phalati tarur itivaj jaḍāyās tasyās tattva-siddhir jalādiṣv antaryāmy-adhiṣṭhitatveneṣṭāsiddher vidhāyaka-śruti-vyākopāc caited evam | na hi jaḍa-prakṛtim uddiśya svargādi-phalakaṃ jyotiṣṭomādi-mokṣa-phalakaṃ dhyānaṃ ca smṛtir vidhatte ‚pi tu cetanam eva bhoktāram uddiśyeti puruṣasyaiva kartṛtvam | tac ca prakṛter iti yad uktaṃ tat tu tad-vṛtti-prācuryād eva yathā kareṇa bibhrati puruṣe karo bibhartīti vyapadeśas tathā prakṛtyā kurvati puruṣe prakṛtiḥ karotīti sa bhaved ity eke, prākṛtair dehādibhir yuktasyaiva puruṣasya yajña-yuddhādi-karma-kartṛtvaṃ, na tu tair viyuktasya śuddhasyety ataḥ prakṛtes tad ity apare