BhG 16.20

syntax

he kaunteya (O son of Kuntī!)
janmani janmani (in birth after birth) mūḍhāḥ (fools) āsurīm yonim (into demoniac wombs) āpannāḥ (who entered)
mām (me) aprāpya eva (indeed after not obtaining)
tataḥ (then) adhamām gatim (to the lowest abode) yānti (they go).

grammar

āsurīm	–	āsurī 2n.1 f. – demoniac, pertaining to the opponents of divinites (from: asura – rival of divinities, demon);
yonim	–	yoni 2n.1 f. – womb, source, origin;
āpannāḥ	–	ā-panna (ā-√pad – to come, to attain) PP 1n.3 m. – who attained;
mūḍhāḥ	–	mūḍha (√muh – to become confused, bewildered, stupefied) PP 1n.3 m. – bewildered, fools;
janmani janmani	–	janman 7n.1 n. – in birth after birth (from: √jan – to be born; repetition meaning continuity);
mām	–	asmat sn. 2n.1 – me;
aprāpya	–	na pra-√āp (to obtain) absol. – after not obtaining;
eva	–	av. – certainly, just, merely;
kaunteya	–	kaunteya 8n.1 m. – O son of Kuntī (from: kunti – the people of Kunti, kuntī – Kuntī, mother of the sons of Pāṇḍu);
tataḥ	–	av. – then, after that, from that, for that reason (from: tat – indeclinable ablative with an ending -tas);
yānti	–	√yā (to go, to attain) Praes. P 1v.3 – they go, they attain;
adhamām	–	adhama 2n.1 f. – lowest, vilest (from: adhas – low, adhara – lower);
gatim	–	gati 2n.1 f. – moving, passage, means, refuge, goal (from: √gam – to go);

textual variants

āsurīṁ yonim → āsurī-yonim (demoniac womb);
aprāpyaiva → aprāpya ca / aprāpyeva (and after not obtaining / as if after not obtaining);

Śāṃkara

āsurīṃ yonim āpannāḥ pratipannāḥ mūḍhāḥ avivekino janmani janmani pratijanma tamobahulāsveva yoniṣu jāyamānāḥ adho gacchanto mūḍhāḥ mām īśvaram aprāpyānāsādya eva he kaunteya, tatas tasmādapi yānty adhamāṃ gatiṃ nikṛṣṭatamāṃ gatim | mām aprāpyaiveti na mat-prāptau kācid api āśaṅkāsti, ataḥ macchiṣṭasādhumārgam aprāpya ity arthaḥ

Rāmānuja

madānukūlyapratyanīkajanmāpannāḥ punar api janmani janmani mūḍhāḥ madviparītajñānā mām aprāpyaiva „asti bhagavān sarveśvaro vāsudevaḥ” iti jñānam aprāpya tataḥ tato janmano ‚dhamām eva gatiṃ yānti

Śrīdhara

kiṃ ca āsurīm iti | te ca mām aprāpyaiva iti eva-kāreṇa mat-prāpti-śaṅkāpi kutas teṣām | mat-prāpty-upāyaṃ san-mārgam aprāpya tato ‚py adhamāṃ kṛmi-kīṭādi-yoniṃ yāntīty uktam | śeṣaṃ spaṣṭam

Madhusūdana

nanu teṣām api krameṇa bahūnāṃ janmanām ante [Gītā 7.19] śreyo bhaviṣyati nety āha āsurīm iti | ye kadācid āsurīṃ yonim āpannās te janmani janmani prati janma mūḍhās tamo-bahulatvenāvivekinas tatas tasmād api yānty adhamāṃ gatiṃ nikṛṣṭatamāṃ gatim | mām aprāpyeti na mat-prāptau kācid āśaṅkāpy asti | ato mad-upadiṣṭaṃ veda-mārgam aprāpyety arthaḥ | eva-kāras tiryak-sthāvarādiṣu veda-mārga-prāpti-svarūpāyogyatāṃ darśayati | tenātyantatamo-bahulatvena veda-mārga-prāpti-svarūpāyogyā bhūtvā pūrva-pūrva-nikṛṣṭa-yonito nikṛṣṭatamām adhamāṃ yonim uttarottaraṃ gacchantīty arthaḥ | he kaunteyeti nija-sambandha-kathanena tvam ito nistīrṇa iti sūcayati | yasmād ekadāsurīṃ yonim āpannānām uttarottaraṃ nikṛṣṭatara-nikṛṣṭatama-yoni-lābho na tu tat-pratīkāra-sāmarthyam atyanta-tamo-bahulatvāt, tasmād yāvan manuṣya-deha-lābho ‚sti tāvan mahatāpi prayatnenāsuryāḥ sampadaḥ parama-kaṣṭatamāyāḥ parihārāya tvarayaiva yathā-śakti daivī sampad anuṣṭheyā śreyo ‚rthibhir anyathā tiryag-ādi-deha-prāptau sādhanānuṣṭhānāyogyatvān na kadāpi nistāro ‚stīti mahat saṅkaṭam āpadyeteti samudāyārthaḥ | tad uktaṃ –
ihaiva naraka-vyādheś cikitsāṃ na karoti yaḥ |
gatvā nirauṣadhaṃ sthānaṃ sa-rujaḥ kiṃ kariṣyati || iti

Viśvanātha

mām aprāpyaiveti na tu māṃ prāpyeti | vaivasvata-manvantararīyāṣṭāviṃśa-caturvyuga-dvāparānte ‚vatīrṇaṃ māṃ kṛṣṇaṃ kaṃsādi-rūpās te prāpya pradviṣanto ‚pi muktim eva prāpnuvantīti bhakti-jñāna-paripākato labhyām api muktiṃ tādṛśa-pāpibhyo ‚py aham apāra-kṛpā-sindhur dadāmi | nibhṛta-marun-mano ‚kṣa dṛḍha-yoga-yujo hṛdi yan munaya upāsate tad-arayo ‚pi yayuḥ smaraṇāt [BhP 10.87.23] iti śrutayo ‚py āhuḥ | ataḥ pūrvoktā mamaiva sarvotkarṣo varīvartīti bhāgavatāmṛta-kārikā yathā –
māṃ kṛṣṇa-rūpiṇaṃ yāvan nāpnuvanti mama dviṣaḥ |
tāvad evādhamaṃ yoniṃ prāpnuvantīti hi sphuṭam || iti | [LBhāg 1.5.83]

Baladeva

nanu bahu-janmānte teṣāṃ kadācit tvad-anukampayāsurayoner vimuktiḥ syād iti cet tatrāha āsurīm iti | te mūḍhā janmany āsurīṃ yonim āpannā mām aprāpyaiva tato ‚py adhamām atinikṛṣṭāṃ śvādi-yoniṃ yānti | mām aprāpyaiva atra eva-kāreṇa mad-anukampāyāḥ sambhāvanāpi nāsti | tal-lābhopāya-yogyā saj-jātir api durlabheti | śrutiś caivam āha – atha kapūya-caraṇā abhyāso ha yat te kapūyāṃ yonim āpadyeran śva-yoniṃ vā śūkara-yoniṃ vā caṇḍāla-yoniṃ vā [ChāU 5.10.7] ity ādikā |
nanv īśvaraḥ satya-saṅkalpatvāday ayogyasyāpi yogyatāṃ śaknuvāt kartum iti cet, śaknuyād eva | yadi saṅkalpayet bījābhāvān na saṅkalpayatīty atas tasyā vaiṣamyam āha sūtrakāraḥ – vaiṣyamya-niarghṛṇye na [Vs 2.1.35] ity ādinā | tataś ca tān aham ity ādi-dvayaṃ sūpapannam | ete nāstikāḥ sarvadā nārakino darśitāḥ | ye tu śāpād asurās tad-anuyāyinaś ca rājanyāḥ pratyakṣe upendra-nṛhari-varāhādau viṣṇau sva-śatru-pakṣatvena vidveṣiṇo ‚pi veda-vaidika-karma-parāḥ sarva-niyantāraṃ kāla-śaktikam apratyakṣaṃ sarveśvaraṃ manyante | te tūpendrādibhir nihatāḥ kramāt tyajanty āsurī-yonim | kṛṣṇena nihatās tu vimucyante ceti | na te veda bāhyāḥ