BhG 15.12

syntax

āditya-gatam (present in the Sun) yat tejaḥ (which splendour),
candramasi ca (and in the Moon) yat [tejaḥ] (which splendour),
agnau ca (and in fire) yat [tejaḥ] (which splendour),
akhilam jagat (the whole world) bhāsayate (it illuminates),
[tvam] (you) tat tejaḥ (that splendour) māmakam (my) viddhi (you must know).

grammar

yat	–	yat sn. 1n.1 n. – which;
āditya-gatam	–	āditya-gata 1n.1 n.; TP: āditye gatam iti – present in the Sun (from: āditya – descendant of Aditi, Sun; √gam – to go, PP gata – gone);
tejaḥ	–	tejas 1n.1 n. – sharpness, heat, splendour, prowess, semen (from: √tij – to sharpen, to tolerate);
jagat	–	jagat 2n.1 n. – world, moving, mankind (from: √gam – to go);
bhāsayate	–	√bhās (to shine, to be bright) caus. Praes. Ā 1v.1 – it causes to shine, it illuminates;
akhilam	–	a-khila 2n.1 n. – whole, complete, without a gap (from: khila – hole, gap);
yat	–	yat sn. 1n.1 n. – which;
candramasi	–	candra-mas 7n.1 m. – in the Moon (from: √cand – to shine, to be bright, candra – Moon; √mas – to measure, mās – month, Moon);
yat	–	yat sn. 1n.1 n. – which;
ca	–	av. – and;
agnau	–	agni 7n.1 m. – in fire (from: √ag – to move tortuously);
tat	–	tat sn. 2n.1 n. – that;
tejaḥ	–	tejas 2n.1 n. – sharpness, heat, splendour, prowess, semen (from: √tij – to sharpen, to tolerate);
viddhi	–	√vid (to know, to understand) Imperat. P 2v.1 – you must know;
māmakam	–	māmaka 2n.1 m. – my, mine;

textual variants

tejo → jyotir (light);
bhāsayate → bhāvayate (it causes to appear);
yac candramasi → yaś caṁdramasi (which in the Moon);

Śāṃkara

yat padaṃ sarvasyāvabhāsakamapy agnyādity ādikaṃ jyotiḥ nāvabhāsayate, yat prāptā ca mumukṣavaḥ punaḥ saṃsārābhimukhāḥ na nivartante, yasya ca padasya upādhi-bhedam anuvidhīyamānāḥ jīvāḥ—ghaṭākāśādayaḥ iva ākāśasya—aṃśāḥ, tasya padasya sarvātmatvaṃ sarvavyavahārāspadatvaṃ ca vivakṣuś caturbhiḥ ślokaiḥ vibhūtisaṃkṣepamāha bhagavān—
yat āditya-gatam ādityāśrayam | kiṃ tat ? tejo dīptiḥ prakāśo jagad bhāsayate prakāśayaty akhilaṃ samastam | yac candramasi śaśabhṛti tejo’vabhāsakaṃ vartate, yac cāgnau hutavahe, tat tejo viddhi vijānīhi māmakaṃ madīyaṃ mama viṣṇos taj jyotiḥ | athavā, āditya-gataṃ tejaś caitanyātmakaṃ jyotir yac candramasi, yac cāgnau vartate tat tejo viddhi māmakaṃ madīyaṃ mama viṣṇos taj jyotiḥ |
nanu sthāvareṣu jaṅgameṣu ca tat samānaṃ caitanyātmakaṃ jyotiḥ | tatra katham idaṃ viśeṣaṇaṃ—yad āditya-gatam ity ādi | naiṣa doṣaḥ, sattvādhikyād vistaratvopapatteḥ | ādity-ādiṣu hi sattvam atyanta-prakāśam atyanta-bhāsvaram | atas tatraivāvistaraṃ jyotir iti tad viśiṣyate, na tu tatraiva tad adhikam iti | yathā hi loke tulye’pi mukha-saṃsthāne na kāṣṭha-kuḍyādau mukham āvirbhavati, ādarśādau tu svacche svacchatare ca tāratamyenāvirbhavati tadvat

Rāmānuja

evaṃ ravicandrāgnīnām indriyasannikarṣavirodhisaṃtamasanirasanamukhenendriyānugrāhakatayā prakāśakānāṃ jyotiṣmatām api prakāśakajñānajyotir ātmā muktāvastho jīvāvasthaś ca bhagavadvibhūtir ity uktam, „tad dhāma pramaṃ mama”, „mamaivāṃśo jīvaloke jīvabhūtas sanātanaḥ” iti / idānīm acitpariṇāmaviśeṣabhūtam ādityādīnāṃ jyotiṣmatāṃ jyotir api bhagavad vibhūtir ity āha
akhilasya jagato bhāsakam eteṣām ādityādīnāṃ yat tejaḥ, tan madīyaṃ tejaḥ tais tair ārādhitena mayā tebhyo dattam iti viddhi

Śrīdhara

tad evaṃ na tad bhāsayate sūrya ity ādinā pārameśvaraṃ paraṃ dhāmoktam | tat-prāptānāṃ cāpunar-āvṛttir uktā | tatra ca saṃsāriṇo ‚bhāvam āśaṅkya saṃsāri-svarūpaṃ dehādi-vyatiriktaṃ darśitam | idānīṃ tad eva pārameśvaraṃ rūpam ananta-śaktitvena nirūpayati yad ity ādi-caturbhiḥ | ādiyādiṣu sthitaṃ yad aneka-prakāraṃ tejo viśvaṃ prakāśayati tat sarvaṃ tejo madīyam eva jānīhi

Madhusūdana

idānīṃ yat padaṃ sarvāvabhāsana-kṣamā apy ādityādayo bhāsayituṃ na kṣamante yat-prāptāś ca mumukṣavaḥ punaḥ saṃsārāya nāvartante yasya ca padasyopādi-bhedam anu vidhīyamānā jīvā ghaṭākāśādaya ivākāśasya kalpitāṃśā mṛṣaiva saṃsāram anubhavanti tasya padasya sarvātmatva-sarva-vyavahārāspadatva-pradarśanena brahmaṇo hi pratiṣṭhāham [Gītā 14.27] iti prāg uktaṃ vivarītuṃ caturbhiḥ ślokair ātmano vibhūti-saṃkṣepam āha bhagavān yad iti | na tatra sūryo bhāti na candra-tārakaṃ nemā vidyuto bhānti kuto ‚yam agniḥ [KaṭhU 2.2.15] ity ādinā | tam eva bhāntam anubhāti sarvaṃ tasya bhāsā sarvam idaṃ vibhāti [KaṭhU 2.2.15] iti śruty-artham anena vyākhyāyate | yad āditya-gataṃ tejaś caitnyātmakaṃ jyotir yac candramasi yac cāgnau sthitaṃ tejo jagad akhilam avabhāsayate tat tejo māmakaṃ madīyaṃ viddhi | yadyapi sthāvara-jaṅgameṣu samānaṃ caitanyātmakaṃ jyotis tathāpi sattvotkarṣeṇādityādīnām utkarṣāt tatraivāvistarāṃ caitanya-jyotir iti tair viśeṣyate yad āditya-gatam ity ādi | yathā tulye ‚pi mukha-saṃnidhāne kāṣṭha-kuḍyādau na mukham āvirbhavati | ādarśādau ca svacche svacchatare ca tāratamyenāvirbhavati tadvad yad āditya-gataṃ teja ity uktvā punas tat tejo viddhi māmakam iti tejo-grahaṇād yad ādityādi-gataṃ tejaḥ prakāśaḥ para-prakāśa-samarthaṃ sita-bhāsvaraṃ rūpaṃ jagad akhilaṃ rūpavad vastu avabhāsayate | evaṃ yac candramasi yac cāgnau jagad-avabhāsakaṃ tejas tan māmākaṃ viddhīti vibhūti-kathanāya dvitīyo ‚py artho draṣṭavyaḥ | anyathā tan māmakaṃ viddhīty etāvad brūyāt tejo-grahaṇam antareṇaiveti bhāvaḥ

Viśvanātha

tad evaṃ jīvasya baddhāvasthāyāṃ yat yat prāpya-vastu tatrāham eva sūrya-candrādy-ātmakaḥ sann upakaromīty āha yad iti tribhiḥ | āditya-sthitaṃ teja eva udaya-parvate prātar uditya jīvasya dṛṣṭādṛṣṭa-bhoga-sādhana-karma-pravartanārthaṃ jagad bhāsayata evaṃ ca yac candramasi aganau ca tat tad akhilaṃ māmakam eva | sūryādi-saṃjño ‚ham eva bhavāmīty arthaḥ | tat tejasa eva tat-tad-vibhūtir iti bhāvaḥ

Baladeva

atha mad-aṃśasya jīvasya saṃsāra-raktasya mumukṣoś ca bhoga-mokṣa-sādhanam aham eveti bhāvenāha yad iti caturbhiḥ | āditye sthitaṃ yat tejo yac candre ‚gnau ca sthitaṃ sat sarvaṃ jagat prakāśayati, tat tejo māmakaṃ madīyaṃ viddhi | uditena sūryeṇa jvalitena ca vahninādṛṣṭa-bhoga-sādhanāni karmāṇi niṣpadyante | timira-jāḍya-nāśādayaś ca sukha-hetavo bhavanti | uditena candreṇa cauṣadhi-poṣa-tāpa-śānti-jyotsnāvihārās tathābhūtā bhavantīti teṣāṃ tat-tat-sādhakaṃ tejo mat-tejo-vibhūtir ity arthaḥ