Bhagavad Gita · Raja Vidya Raja Guhya YogaChapter 9, Shloka 1 (9.1)
Original Sanskrit · श्रीभगवान्
श्रीभगवानुवाच
इदं तु ते गुह्यतमं प्रवक्ष्याम्यनसूयवे
ज्ञानं विज्ञानसहितं यज्ज्ञात्वा मोक्ष्यसेऽशुभात्
॥ 9.1 ॥
idaṃ tu te guhyatamaṃ pravakṣyāmyanasūyave
jñānaṃ vijñānasahitaṃ yajjñātvā mokṣyase'śubhāt
Translation
"The Blessed Lord said: Now to you, who do not find fault, I shall tell this most secret knowledge, together with realised knowledge (vijnana), knowing which you will be freed from what is inauspicious (the bondage of samsara)."
Interpretation
Shankaracharya — knowledge of Brahman. idaṃ brahma-jñānaṃ vakṣyamāṇam uktaṃ ca pūrvaṣu adhyāyeṣu — this knowledge of Brahman, spoken of in earlier chapters and to be spoken of further on; idam eva tu samyag-jñānaṃ sākṣāt mokṣa-prāpti-sādhanam "vāsudevaḥ sarvam" iti — this right knowledge alone is the direct means to liberation — "Vasudeva is all"; evidence Brihadaranyaka 2.4.6, Chhandogya 6.2.1. Vijñāna-sahitam anubhava-yuktam; aśubhāt saṃsāra-bandhanāt.
Acharya Ramanuja — worship in the form of devotion. Idaṃ tu te guhyatamaṃ bhakti-rūpam upāsanākhyaṃ jñānaṃ — the most secret knowledge is worship in the form of bhakti (devotion); vijñāna-sahitam upāsana-gati-viśeṣa-jñāna-sahitam — together with knowledge of the particular methods of worship; anasūyave … mad-viṣayaṃ sakaletara-visajātīyam aparimita-prakāraṃ māhātmyaṃ śrutvā evam eva saṃbhavati iti manvānāya — to one who, hearing of my unique and boundless greatness, accepts "yes, it must be so".
The difference: Shankara — the most secret = knowledge of Brahman; Ramanuja — the most secret = bhakti.
AI-assisted draft translation — under review.