BhG 14.8

syntax

he bhārata (O descendant of Bhārata!),
[tvam] (you) ajñāna-jam tamaḥ tu (tamas born from ignorance) sarva-dehinām (of all the embodied ones) mohanam (bewildering) viddhi (you must know).
tat [tamas] (that tamas) pramādālasya-nidrābhiḥ (by madness, laziness and sleepiness) [dehinam] (the embodied one) nibadhnāti (it binds).

grammar

tamaḥ	–	tamas 2n.1 n. – darkness, gloom, dullness, passivity, one of the three guṇas (from: √tam – to choke, to faint, to perish, to stop);
tu	–	av. – but, then, or, and;
ajñāna-jam	–	ajñāna-ja 2n.1 n. – born from ignorance (from: jñā – to know, to understand, a-jñāna – ignorance; √jan – to be born, ja – suffix: born);
viddhi	–	√vid (to know, to understand) Imperat. P 2v.1 – you must know;
mohanam	–	mohana 2n.1 m. – bewildering, perplexing (from: √muh – to become confused, bewildered, stupefied; moha – bewilderment, confusion);
sarva-dehinām	–	sarva-dehin 6n.3 m.; sarvāṇāṁ dehinām iti – of all the embodied ones (from: sarva – all, whole; √dih – to anoint, to smear, deha – a form, shape, body; dehin = dehavant = dehābhimānin – who possesses a body, thinking about oneself as a body);
pramādālasya-nidrābhiḥ	–	pramāda-ālasya-nidrā 3n.3 f.; DV: pramadena ca ālasyena ca nidrayā ceti – by madness, laziness and sleepiness (from: pra-√mad – to enjoy, to delight, to delude, pramāda – madness; √las – to shine, to glitter, to play, alasa – inactive, without energy, lazy, ālasya – inactivity, laziness, idleness; ni-√xdrā – to fall asleep, ni-drā – sleep, sloth);
tat	–	tat sn. 1n.1 n. – that;
nibadhnāti	–	ni-√bandh (to bind, to fetter) Praes. P 1v.1 – it binds;
bhārata	–	bhārata 8n.1 m. – O descendant of Bhārata;

textual variants

tamas → tatas (therefore);
mohanaṁ → mohinaṁ (bewildered);

Śāṃkara

tamas tṛtīyo guṇo’jñāna-jam ajñānāj jātam ajñāna-jaṃ viddhi | mohanaṃ moha-karam aviveka-karaṃ sarva-dehināṃ sarveṣāṃ dehavatām | pramādālasya-nidrābhiḥ pramādaś cālasyaṃ ca nidrā ca pramādālasya-nidrās tābhiḥ pramādālasya-nidrābhis tat tamo nibadhnāti bhārata

Rāmānuja

jñānād anyad iha ajñānam abhipretam / jñānaṃ vastuyathātmyāvabodhaḥ; tasmād anyat tadviparyayajñānam / tamas tu vastuyāthātmyaviaparītaviṣayajñānajam / mohanaṃ sarvadehinām / moho viparyayajñānam; viparyayajñānahetur ityarthaḥ / tat tamaḥ pramādālasyanidrāhetutayā taddvāreṇa dehinaṃ nibadhnāti / pramādaḥ kartavyāt karmaṇo ‚nyatra pravṛttihetubhūtam anavadhānam / ālasyam karmasv anārambhasvabhāvaḥ; stabdhateti yāvat / puruṣasyendriyapravartanaśrāntyā sarvendriyapravartanoparatir nidrā; tatra bāhyendriyapravartanoparamaḥ svapnaḥ; manaso ‚py uparatiḥ suṣuptiḥ

Śrīdhara

tamaso lakṣaṇaṃ bandhakatvaṃ cāha tama iti | tamas tv ajñānāj jātam āvaraṇa-śakti-pradhānāt prakṛty-aṃśād udbhutaṃ viddhīty arthaḥ | ataḥ sarveṣāṃ dehināṃ mohanaṃ bhrānti-janakam | ataeva pramādenālasyena nidrayā ca tat tamo dehinaṃ nibadhnāti | tatra pramādo ‚navadhānam | ālasyam anudyamaḥ | nidrā cittasyāvasādāl layaḥ

Madhusūdana

tu-śabdaḥ sattva-rajopekṣayā viśeṣa-dyotanārthaḥ | ajñānād āvaraṇa-śakti-rūpād udbhūtam ajñāna-jaṃ tamo viddhi | ataḥ sarveṣāṃ dehināṃ mohanam aviveka-rūpatvena bhrānti-janakam | pramādenālasyena nidrayā ca tat tamo nibadhnāti | dehinam ity anuṣajyate | he bhārata | pramādo vastu-vivekāsāmarthyaṃ sattva-kārya-prakāśa-virodhī | ālasyaṃ pravṛtty-asāmarthyaṃ rajaḥ-kārya-pravṛtti-virodhi | ubhaya-virodhinī tamo-guṇālambanā vṛttir nidreti vivekaḥ

Viśvanātha

ajñānam ajñānāt svīya-phalāt jātaṃ pratītam anumitaṃ bhavatīty ajñānajam ajñāna-janakam ity arthaḥ | mohanaṃ bhrānti-janakam | pramādo ‚navadhānam | ālasyam anudyamaḥ | nidrā cittasyāvasādāl layaḥ

Baladeva

tamas tv iti | tu-śabdaḥ pūrva-dvitīyād viśeṣa-dyotakaḥ | vastu-yāthātmyāvagamo jñānaṃ tad-virodhy-āvarakatā-pradhānaṃ prakṛty-aṃśo ‚jñānam | tasmāj jātaṃ tamo ætaḥ sarva-dehināṃ mohanaṃ viparyaya-jñāna-janakam | tathā ca vastu-yāthātmya-jñānāvarakaṃ viparyaya-jñāna-janakaṃ tamaḥ iti | tat tamaḥ pramādādibhiḥ svakāryaiḥ puruṣaṃ nibadhnāti | tatra pramādo ‚navadhānam akārye karmaṇi pravṛtti-rūpaṃ sattva-kārya-prakāśa-virodhī | ālasyam anudyamaḥ, rajaḥ-kārya-pravṛtti-virodhi | tad-ubhaya-virodhinī tu nidrā cittasyāvasādātmeti