BhG 3.38

syntax

yathā (as) dhūmena (by smoke) vahniḥ (fire) āvriyate (is covered),
[yathā] ca (and as) malena (by dust) ādarśaḥ (mirror) [āvriyate] (is covered),
yathā (as) ulbena (by the womb) garbhaḥ (embryo) āvṛtaḥ (covered) [asti] (it is),
tathā (so) tena (by that) idam (this) āvṛtam (covered) [asti] (it is).

grammar

dhūmena	–	dhūma 3n.1 m. – by smoke (from: √dhū – to shake, to kindle);
āvriyate	–	ā-√vṛ (to cover) Praes. pass. 1v.1 – it is covered;
vahniḥ	–	vahni 1n.1 m. – fire (from: √vah – to carry);
yathā	–	av. – as (correlative of: tathā);
ādarśaḥ	–	ā-darśa 1n.1 m. – mirror (from: ā-√dṛś – to show, to be seen);
malena	–	mala 3n.1 n. – by impurity, by dust, by dirt;
ca	–	av. – and;
yathā	–	av. – as (correlative of: tathā);
ulbena	–	ulba 3n.1 n. – by cover, cave, the womb;
āvṛtaḥ	–	ā-vṛta (ā-√vṛ – to cover) PP 1n.1 m. – covered;
garbhaḥ	–	garbha 1n.1 n. – embryo, interior (from: √grah – to take or √gṝ – to call, to emit);
tathā	–	av. – in that manner, so, in like manner;
tena	–	tat sn. 3n.1 m. – by that;
idam	–	idam 1n.1 n. – this;
āvṛtam	–	ā-vṛta (ā-√vṛ – to cover) PP 1n.1 n. – covered;

textual variants

dhūmenāvriyate → dhūmenāvrīyate / vidhūmenāyate / dhūmenādriyate / dhūmenāpi hito (by smoke covered / by smoke come / by smoke it is attended / even by fire stroke);
tathā tenedam āvṛtam → tathā tenāyam āvṛtaḥ (so by that this covered);

Śāṃkara

The key:
an excerpt from the commented verse
quotes from the scriptures
starting polemic

He now illustrates how it is our foe:		kathaṃ vairī? iti dṛṣṭāntaiḥ pratyāyayati —
As fire is surrounded by smoke, as a mirror by rust, as the fetus is enclosed in the womb, so is this covered by it.		dhūmenāvriyate vahnir yathādarśo malena ca | yatholbenāvṛto garbhas tathā tenedam āvṛtam ||3.38||
As a bright fire is surrounded by dark smoke co-existent with it so this is covered with desire.		dhūmena sahajenāvriyate vahniḥ prakāśātmako ’prakāśātmakena, yathā vā ādarśo malena ca, yatholbena ca jarāyuṇā garbha-veṣṭanena cāvṛta ācchādito garbhas tathā tenedam āvṛtam ||3.38||

Rāmānuja

yathā dhūmena vahnir āvriyate, yathā ādarśo malena, yathā ca ulbenāvṛto garbhaḥ, tathā tena kāmena idaṃ jantujātam āvṛtam

Śrīdhara

kāmasya vairitvaṃ darśayati dhūmeneti | dhūmena sahajena yathā vahnir āvriyata ācchādyate | yathā cādarśo malenāgantukena | yathā colbena garbhaveṣṭana-carmaṇā garbhaḥ sarvato niruddha āvṛtaḥ | tathāprakāra-trayeṇāpi tena kāmenāvṛtam idam

Madhusūdana

tasya mahā-pāpmatvena vairtvam eva dṛṣṭāntaiḥ spaṣṭayati dhūmeneti | tatra śarīrārambhāt prāg-antaḥ-karaṇa-sthālabdha-vṛttikatvāt sūkṣmaḥ kāmaḥ śarīrārambhakeṇa karmaṇā sthūla-śarīrāvacchinne labdha-vṛttike ‚ntaḥkaraṇe kṛtābhivyaktiḥ san sthūlo bhavati | sa eva viṣayasya cintyamānatāvasthāyāṃ punaḥ punar udricyamānaḥ sthūlataro bhavati | sa eva punar viṣayasya bhujyamānatāvasthāyām atyantodrekaṃ prāptaḥ sthūlatamo bhavati | tatra prathamāvasthāyāṃ dṛṣṭāntaḥ — yathā dhūmena sahajenāprakāśātmakena prakāśātmako vahnir āvriyate | dvitīyāvasthāyāṃ dṛṣṭāntaḥ – yathādarśo malenāsahajenādarśotpatty-anantaram udriktena | ca-kāro ‚vāntara-vaidharmya-sūcanārtha āvriyata iti kriyānukarṣaṇārthaś ca | tṛtīyāvasthāyāṃ dṛṣṭāntaḥ – yatholbena jarāyuṇā garbha-veṣṭana-carmaṇātisthūlena sarvato nirudhyāvṛtas tathā prakāra-trayeṇāpi tena kāmenedam āvṛtam |

atra dhūmenāvṛto ‚pi vahnir dāhādi-lakṣaṇaṃ sva-kāryaṃ karoti | malenāvṛtas tv ādarśaḥ pratibimba-grahaṇa-lakṣaṇaṃ svakāryaṃ na karoti | svacchatā-dharma-mātra-tirodhānāt svarūpatas tūpalabhyata eva | ulbenāvṛtas tu garbho na hasta-pādādi-prasāraṇa-rūpaṃ sva-kāryaṃ karoti na vā svarūpata upalabhyata iti viśeṣaḥ

Viśvanātha

na ca kasyacid evāyaṃ vairy api tu sarvasyaiveti sa-dṛṣṭāntam āha dhūmeneti | kāmasyāgāḍhatve gāḍhatve ‚tigāḍhatve ca krameṇa dṛṣṭāntāḥ | dhūmenāvṛto ‚pi malino vahnir dāhādi-lakṣaṇaṃ sva-kāryaṃ tu karoti | malenāvṛto darpaṇaṃ tu svacchatā-dharma-tirodhānād bimba-grahaṇaṃ sva-kāryaṃ na karoti svarūpatas tūpalabhyate | ulbena jarāyūṇāvṛto garbhas tu sva-kāryaṃ kara-caraṇādi-prasāraṇaṃ na karoti, na vā svarūpata upalabhyata iti | evaṃ kāmasyāgāḍhatve paramārtha-smaraṇaṃ kartuṃ śaknoti | gāḍhatve na śaknotīti gāḍhatve tv acetanam eva syād idaṃ jagad eva

Baladeva

mṛdu-madhya-tīvra-bhāvena trividhasya kāmasya dhūma-malolbaneti krameṇa dṛṣṭāntān āha dhūmenet | yathā dhūmenāvṛto ‚nujjvalo ‚pi vahnir auṣṇādikaṃ kiṃcit karoti malenāvṛto darpaṇaḥ svacchatā-tirodhānāt pratibimbaṃ na śaknoti grahītum ulbena jarā-guṇāvṛto garbhas tu pādādi-prasārarṃ na śaknoti kartuṃ na copalabhyate | tathā mṛdunā kāmenāvṛtaṃ jñānaṃ kathaṃcit tattvārthaṃ grahītuṃ śaknoti madhyenāvṛtaṃ na śaknoti | tīvreṇāvṛtaṃ tu prasartum api na śaknoti, na ca pratīyata ity arthaḥ