BhG 18.75

syntax

aham (I) vyāsa-prasādāt (from the mercy of Vyāsa) etat param guhyam (this supreme secret) yogam (yoga) kathayataḥ (from one who is telling) sākṣāt (directly) yogeśvarāt kṛṣṇāt (from Kṛṣṇa, master of yoga) svayam (personally) śrutavān [āsam] (I was one who heard).

grammar

vyāsa-prasādāt	–	vyāsa-prasāda 5n.1 m.; TP: vyāsasya prasādād iti – from satisfaction of Vyāsa (from: vi-√as – to divide, to dispose, to arrange, vyāsa – Vyāsa, arranging; pra-√sad – to settle down, to be pleased, to be successful, prasāda – satisfaction, favour, calmness, clearness, success, kindness);
śrutavān	–	śruta (√śru – to hear, to listen) PP pas.x 1n.1 m. – one who heard;
etat	–	etat sn. 2n.1 n. – this;
guhyam	–	guhya (√xguh – to cover, to hide) PF 2n.1 n. – to be hidden, secret ;
aham	–	asmat sn. 1n.1 – I;
param	–	para 2n.1 n. – beyond, ancient, final, the best, the supreme;
yogam	–	yoga 2n.1 m. – yoga, yoking, application, a means, one of the schools of Hindu philosophy (from:√yuj – to yoke, to join, to engage);
yogeśvarāt	–	yoga-īśvara 5n.1 m.; TP: yogasyeśvarād iti – from the lord of yoga (from: √yuj – to yoke, to join, to engage, yoga – yoga, yoking, application, a means, one of the schools of Hindu philosophy; √xīś – to own, to reign, īśa / īśvara – ruler, lord);
kṛṣṇāt	–	kṛṣṇa 5n.1 m. – from the dark one, from Kṛṣṇa;
sākṣāt	–	av. – before one’s eyes, directly, openly, in person (from: sa-akṣa – with the eyes);
kathayataḥ	–	kathayant (√kath – to tell, to narrate) PPr 5n.1 – from one who is telling;
svayam	–	av. – personally, on one’s own;

textual variants

etad → imaṁ / etaṁ (this);
guhyam ahaṁ → guhyatamaṁ / guhyataraṁ (more secret / the most secret);
param → mahat (great);
etad guhyam ahaṁ param → etaṁ guhyam anuttamam (this secret and incomparable);
yogeśvarāt → yogīśvarāt (from the lord of the yogīs);
kathayataḥ → kathayatā / tu kathitaḥ (by one who is telling / just told);

Śāṃkara

taṃ cemaṃ—
vyāsa-prasādāt tato divya-cakṣur-lābhāt, śrutavān imaṃ saṃvādaṃ guhyatamaṃ paraṃ yogam, yogārthatvād grantho’pi yogaḥ, saṃvādam imaṃ yogam eva vā yogeśvarāt kṛṣṇāt sākṣāt kathayataḥ svayam, na paramparayā

Rāmānuja

vyāsaprasādād vyāsānugraheṇa divyacakṣuśśrotralābhād etat paraṃ yogākhyaṃ guhyaṃ yogeśvarāj jñānabalāiśvaryavīryaśaktitejasāṃ nidher bhagavataḥ kṛṣṇāt svayam eva kathayataḥ sākṣāc śrutavān aham

Śrīdhara

ātmanas tac-chravaṇe sambhāvanām āha vyāsa-prasādād iti | bhagavatā vyāsena divyaṃ cakṣuḥ śrotrādi machyaṃ dattam ato vyāsasya prasādāt etat ahaṃ śrutavān asmi | kiṃ tad ity apekṣāyām āha paraṃ yogaṃ | paratvaṃ āviṣkaroti yogeśvarāt śrī-kṛṣṇāt svayam eva sākṣāt kathayataḥ śrutavān iti

Viśvanātha

commentary under the verse BhG 18.74

Baladeva

vyavahita-tat-saṃvāda-śravaṇe sva-yogyatām āha vyāseti | vyāsa-prasādāt tad-datta-divya-cakṣuḥ-śrotrādi-lābha-rūpād etad guhyaṃ śrutavān | kim etad ity āha param yogam iti | karma-yogaṃ jñāna-yogaṃ bhakti-yogaṃ cety arthaḥ | paratvaṃ sampādayati yogeśvarād iti | deva-mānavādi-nikhila-prāṇināṃ svabhāvya-sambandho yogaḥ | teṣām adhīśān niyantuḥ svayaṃ-rūpāt kṛṣṇāt sva-mukhenaiva, na tu paramparayā kathayataḥ | śrutavān asmīti sva-bhāgyaṃ ślāghyate