BhG 15.14

syntax

aham (I) vaiśvānaraḥ (the fire of digestion) bhūtvā (after becoming)
prāṇinām (of those breathing) deham (body) āśritaḥ (taken shelter)
prāṇāpāna-samāyuktaḥ (endowed with inhale and exhale) catur-vidham annam (four kinds of food) pacāmi (I digest).

grammar

aham	–	asmat sn. 1n.1 – I;
vaiśvānaraḥ	–	vaiśvā-nara 1n.1 m. – belonging to all people, omnipresent, Sun, the fire of digestion (from: √viś – to enter, viśva – all, whole, world; nṛ – man, mankind, nara – a man, a person);
bhūtvā	–	√bhū (to be) absol. – after becoming;
prāṇinām	–	prāṇin 6n.3 m. – of the owners of life, of living beings (from: pra-√an – to breath upwards → √prāṇ – to breath, to live, prāṇa – breath, life; -in, -min, -vin – sufixes meaning one who possesses);
deham	–	deha 2n.1 m. – body (from: √dih – to anoint, to smear, deha – a form, shape, body);
āśritaḥ	–	āśrita (ā-√śri – to  adhere, to lean on, to rest on, to depend on) PP 1n.1 m. – taken shelter (of whom? – requires accusative);
prāṇāpāna-samāyuktaḥ	–	prāṇa-apāna-samāyukta 1n.1 f.; DV / TP: prāṇena ca apānena ca samāyukta iti – endowed with inhale and exhale (from: pra-√an – to breath upwards → √prāṇ – to breath, to live, prāṇa – breath, air going upwards; ap-√an – to breath downwards, apāna – air going downwards; sam-ā-√yuj – to yoke, to join, to engage together, PP sam-ā-yukta – yoked, endowed with);
pacāmi	–	√pac (to cook, to digest) Praes. P 3v.1 – I cook, I digest;
annam	–	anna (√ad – to eat) PP 2n.1 n. – food;
catur-vidham	–	catur-vidha 2n.1 n. – fourfold, of four kinds (from: catur – four; vi-√dhā – to divide, vidhā – division, part; four kinds of food: bhokṣyam – to be chewed, bhojyam – to be eaten without chewing, lehyam – to be licked, coṣyam – to be sucked);

textual variants

vaiśvānaro → viśvā-naro (relating to all people);
āśritaḥ → āsthitaḥ / āviṣṭaḥ (situated / who entered);
prāṇāpāna-samāyuktaḥ → prāṇāpānaḥ samāyuktaḥ / prāṇāpāna-sakhaṁ bhūtvā (endowed, being inhale and exhale / after becoming friend of inhale and exhale);

Śāṃkara

kiṃ ca—
aham eva vai vaiśvānara udara-stho’gnir bhūtvā—ayam agnir vaiśvānaro yo’yam antaḥ puruṣe yenedam annaṃ pacyate yad idam adyate [bhāvātmauttaṃ 5.9.1] ity ādi-śruteḥ | vaiśvānaraḥ san prāṇināṃ prāṇavatāṃ deham āśritaḥ praviṣṭaḥ prāṇāpāna-samāyuktaḥ prāṇāpānābhyāṃ samāyuktaḥ saṃyuktaḥ pacāmi paṅkti karomy annam aśanaṃ caturvidhaṃ catuṣprakāraṃ bhojyaṃ bhakṣyaṃ coṣyaṃ lehyaṃ ca | bhoktā vai vānaro’gniḥ | agner bhojyam annaṃ somaḥ | tad etad ubhayam agnīṣomau sarvam iti paśyato’nna-doṣa-lepo na bhavati

Rāmānuja

ahaṃ vaiśvānaro jāṭharānalo bhūtvā sarveṣāṃ prāṇināṃ deham āśritaḥ tair bhuktaṃ khādyacūṣyalehyapeyātmakaṃ caturvidham annaṃ prāṇāpānavṛttibhedasamāyuktaḥ pacāmi

Śrīdhara

kiṃ ca aham iti | aham īśvara eva vaiśvānaro jaṭharāgnir bhūtvā prāṇināṃ dehasyāntaḥ praviśya prānāpānābhyāṃ ca tad-uddīpakābhyāṃ sahitaḥ prāṇibhir bhuktaṃ bhakṣyaṃ bhojyaṃ lehyaṃ coṣyaṃ ceti caturvidham annaṃ pacāmi | tatra yad dantair avakhaṇḍyāvakhaṇḍya bhakṣyate pūpādi tad bhakṣyam | yat tu kevalaṃ jihvayā viloḍya nigīryate pāyasādi tad bhojyam | yaj jihvāyāṃ nikṣipya rasāsvādena kramaśo nigīryate dravībhūtaṃ guḍādi tal lehyam | yat tu daṃṣṭrādibhir niṣpīḍya sārāṃśaṃ nigīryāvaśiṣṭaṃ tyajyata ikṣu-daṇḍādi tac coṣyam iti caturvidho ‚sya bhedaḥ

Madhusūdana

kiṃ ca aham iti | aham īśvara eva vaiśvānaro jaṭharo ‚gnir bhūtvā ayam agnir vaiśvānaro yo ‚yam antaḥ puruṣe yenedam annaṃ pacyate yad idam adyate [BAU 5.9.1] ity ādi śruti-pratipāditaḥ san prāṇināṃ sarveṣāṃ deham āśrito ‚ntaḥ praviṣṭaḥ prānāpānābhyāṃ tad-uddīpakābhyāṃ saṃyuktaḥ saṃdhukṣitaḥ san pacāmi prāṇibhir bhuktam annaṃ caturvidham bhakṣyaṃ bhojyaṃ lehyaṃ coṣyaṃ ceti | tatra yad dantair avakhaṇḍyāvakhaṇḍya bhakṣyate pūpādi tad bhakṣyam | yat tu kevalaṃ jihvayā viloḍya nigīryate sūpaudanādi tad bhojyam | yaj jihvāyāṃ nikṣipya rasāsvādena nigīryate kiṃcid dravībhūtaṃ guḍa-rasālā-śikhariṇy-ādi tal lehyam | yat tu dantair niṣpīḍya rasāṃśaṃ nigīryāvaśiṣṭaṃ tyajyate yathekṣu-daṇḍādi tac coṣyam iti bhedaḥ | bhoktā yaḥ so ‚gnri vaiśvānaro yad bhojyam annaṃ sa somas tad etad ubhayam agnīṣomau sarvam iti dhyāyato ‚nna-doṣa-lepo na bhavatīty api draṣṭavyam

Viśvanātha

vaiśvānaro jaṭharānalaḥ prāṇāpānābhyāṃ tad uddīpakābhyāṃ sahitaś caturvidhaṃ bhakṣyaṃ bhojyaṃ lehyaṃ coṣyam | bhakṣyaṃ danta-cchedyaṃ bhṛṣṭa-canakādi bhojyaṃ modakādi | lehyaṃ guḍādi | coṣyam ikṣu-daṇḍādi

Baladeva

bhogyānām annādīnāṃ pāka-hetuś cāham evety āha aham iti | vaiśvānaro jaṭharāgnis tac-charīrako bhūtvā prāṇināṃ sarveṣāṃ deham udaram āśritaḥ prānāpānābhyāṃ tad-uddīpakābhyāṃ samāyuktaś ca sann ahaṃ tair bhuktaṃ caturvidham annaṃ pacāmi pākaṃ nayāmi | śrutiś caivam āha ayam agnir vaiśvānaro yo ‚yam antaḥ puruṣe yenedaṃ annaṃ pacyate ity ādinā | tathā cāham eva jāṭharāgni-śarīras tad-upakārīty evam āha sūtrakāraḥ — śabdādibhyo ‚ntaḥ pratiṣṭhānāc ca ity ādinā | annasya cāturvidhyaṃ ca bhakṣyaṃ bhojyaṃ lehyaṃ cūṣyaṃ ceti bhedāt | danta-cchedyaṃ caṇaka-pūpādi | bhakṣyaṃ carvyam iti cocyate | modakaudana-sūpādi bhojyaṃ | pāyasa-guḍa-madhv-ādi lehyaṃ | pakvāmrekṣu-daṇḍādi cūṣyaṃ | soma-vaiśvānarayoḥ svābhedenoktiḥ sva-vyāpyatvād iti bodhyam