BhG 3.41

syntax

he bharatarṣabha (O best of the Bharatas!),
tasmāt (therefore) tvam (you) ādau (in the beginning) indriyāṇi (the senses) niyamya (after restraining),
enam (this) jñāna-vijñāna-nāśanam (destroyer of knowledge and wisdom) pāpmānam (the evil) hi prajahi (indeed you must kill).

grammar

tasmāt	–	av. – therefore (from: tat sn. 5n.1 m. – from that);
tvam	–	yuṣmat sn. 1n.1 – you;
indriyāṇi	–	indriya 2n.3 n. – the senses (from: √ind – to be powerful);
ādau	–	av. – in the beginning (from: ādi – beginning; locative);
niyamya	–	ni-√yam (to restrain) absol. – after restraining;
bharata-rṣabha	–	bharata-rṣabha 8n.1 m.; TP: bharatāṇām ṛṣabha iti – O best of the Bharatas (from: √bhṛ – to hold or bharata – king Bharata, maintained, actor, in plural – the descendants of Bharata; ṛṣabha – bull, the best of any kind);
pāpmānam	–	pāpman 2n.1 m. – evil, misfortune, sin;
prajahi	–	pra-√han (to strike, to beat, to kill) Imperat. P 2v.1 – you must kill; or: prajahihi → pra-√hā (to leave, to abandon) Imperat. P 2v.1 – you must leave;
hi	–	av. – because, just, indeed, surely;
enam	–	etat sn. 2n.1 m. – this;
jñāna-vijñāna-nāśanam	–	jñāna-vijñāna-nāśana 2n.1 m.; BV: yena jñānasya vijñānasya ca nāśanam asti tam – by which there is a destruction of knowledge and wisdom (from: √jñā – to know, to understand, jñāna – knowledge, wisdom, intelligence; vi-jñāna – comprehension, understanding, wisdom; √naś – to destroy, to vanish, nāśa – destruction, loss, nāśana – destruction, removal);

textual variants

niyamya → niyatya (after endeavouring);
prajahi hy enaṃ → prajahī hy enaṃ;

Śāṃkara

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

How to kill out desire. Wherefore:		yata evaṃ —
Therefore, O Lord of the Bharatas, restrain the senses first, do thou cast off this sinful thing which is destructive of knowledge and wisdom.		tasmāt tvam indriyāṇy ādau niyamya bharatarṣabha | pāpmānaṃ prajahi hy enaṃ jñāna-vijñāna-nāśanam ||3.41||
		tasmāt tvam indriyāṇy ādau pūrvam eva niyamya vaśīkṛtya bharatarṣabha pāpmānaṃ pāpācāraṃ kāmaṃ prajahi hi parityaja enaṃ prakṛtaṃ vairiṇaṃ jñāna-vijñāna-nāśanaṃ |
Jñāna is the knowledge of the Self and other things acquired from the śastra (scripture) and from a teacher (acharya). Vijñāna is the personal experience of the things so taught. Do thou cast off from you the destroyer of jñāna and vijñāna which lead to the highest good.		jñānaṃ śāstrata ācāryataś cātmādīnām avabodhaḥ | vijñānaṃ viśeṣatas tad-anubhavas tayor jñāna-vijñānayoḥ śreyaḥ-prāpti-hetvor nāśanaṃ nāśa-karaṃ prajahihi ātmanaḥ parityajety arthaḥ ||3.41||

Rāmānuja

yasmāt sarvendriyavyāpāroparatirūpe jñānayoge pravṛttasyāyaṃ kāmarūpaḥ śatruḥ viṣayābhimukhyakaraṇena ātmani vaimukhyaṃ karoti, tasmāt prakṛtisaṃsṛṣṭatayendriyavyāpārapravaṇastvam ādau mokṣopāyārambhasamaya eva, indriyavyāpārarūpe karmayoge indriyāṇi niyamya, enaṃ jñānavijñānanāśanam ātmasvarūpaviṣayasya jñānasya tadvivekaviṣayasya ca nāśanaṃ pāpmānaṃ kāmarūpaṃ vairiṇaṃ prajahi nāśaya

Śrīdhara

yasmād evaṃ tasmād iti | tasmād ādau vimohāt pūrvam evendriyāṇi mano buddhiṃ ca niyamya pāpmānaṃ pāpa-rūpam enaṃ kāmaṃ hi sphuṭaṃ prajahi ghātaya | yad vā prajahihi parityaja | jñānam ātma-viṣayaṃ | vijñānaṃ nididhyāsanajam | tam eva dhīro vijñāya prajñāṃ kurvīta iti śruteḥ

Madhusūdana

yasmād evam | yasmād indriyādhiṣṭhānaḥ kāmo dehinaṃ mohayati tasmāt tvam ādau mohanāt pūrvaṃ kāma-nirodhāt pūrvam iti vā | indriyāṇi śrotrādīni niyamya vaśīkṛtya | teṣu hi vaśīkṛteṣu mano-buddhyor api vaśīkaraṇaṃ sidhyati saṅkalpādhyavasāyayor bāhyendriya-pravṛtti-dvāraivānartha-hetutvāt | ata indriyāṇi mano buddhir iti pūrvaṃ pṛthaṅ-nirdiśyāpīhendriyāṇīty etāvad uktam | indriyatvena tayor api saṅgraho vā | he bharatarṣabha mahā-vaṃśa-prabhūtatvena samartho ‚si | pāpmānaṃ sarva-pāpa-mūla-bhūtam enaṃ kāmaṃ vairiṇaṃ prajahihi parityaja hi sphuṭaṃ prajahi prakarṣeṇa mārayeti vā | jahi śatrum ity upasaṃhārāc ca | jñānaṃ śāstrācāryopadeśa-jaṃ parokṣaṃ vijñānam aparokṣaṃ tat-phalaṃ tayor jñāna-vijñānayoḥ śreyaḥ-prāpti-hetvor nāśanam

Viśvanātha

vairiṇaḥ khalv āśraye jite sati vairī jīyata iti nītir ataḥ kāmasyāśrayeṣv indriyādiṣu yathottaraṃ durjayatvādhikyam | ataḥ prathama-prāptānīndriyāṇi durjayāny apy uttarāpekṣayā sujayāni | prathamaṃ te jīyantām ity āha tasmād iti | indriyāṇi niyamyena yadyapi para-strī-para-dravyādy-apaharaṇe durnivāraṃ mano gacchaty eva | tad api tatra tatra netra-śrotra-kara-caraṇādīndriya-vyāpāra-stha-gaṇanād indriyāṇi na gamayety arthaḥ | pāpmānam atyugraṃ kāmaṃ jahītīndriya-vyāpārastha-gaṇanam atikālena mano ‚pi kāmād vicyutaṃ bhavatīti bhāvaḥ

Baladeva

yasmād ayaṃ kāma-rūpo vairī nikhilendriya-vyāpāra-virati-rūpāyātma-jñānāyodyatasya viṣaya-rasa-pravaṇair indriyair jñānam āvṛṇoti tasmāt prakṛti-sṛṣṭa-dehādimāṃs tvam ādāv ātma-jñānodayāyārambha-kāla evendriyāṇi sarvāṇi tad-vyāpāra-rūpe niṣkāme karma-yoge niyamya pravaṇāni kṛtvā enaṃ pāpmānaṃ kāmaṃ śatruṃ prajahi vināśaya | hi yasmāj jñānasya śāstrīyasya dehādi-viviktātma-viṣayakasya vijñānasya ca tādṛg-ātmānubhavasya nāśanam āvarakam