18.64

सर्वगुह्यतमं भूयः
शृणु मे परमं वचः ।
इष्टोऽसि मे दृढमिति
ततो वक्ष्यामि ते हितम् ॥

sarvaguhyatamaṃ bhūyaḥ śṛṇu me paramaṃ vacaḥ
iṣṭo 'si me dṛḍham iti tato vakṣyāmi te hitam

Kṛṣṇa (कृष्ण) is still speaking, to Arjuna (अर्जुन).

The verse

Hear again my supreme word, the most secret of all; because you are firmly dear to me, I shall speak what is good for you.

नेपालीमा

फेरि मेरो सर्वोच्च वचन सुन, सबैभन्दा गुप्त। तिमी मलाई अटल रूपमा प्यारो भएकाले, म तिम्रो हितको कुरा भन्नेछु।

Where it sits

Because Arjuna (अर्जुन) is dear, he takes the speech back to say what is good for him, the four stands next and the refuge in 18.66.

Split: सर्व-गुह्यतमम् + भूयः + शृणु + मे + परमम् + वचः + इष्टः + असि + मे + दृढम् + इति + ततः + वक्ष्यामि + ते + हितम्

sarva-guhyatamam + bhūyaḥ + śṛṇu + me + paramam + vacaḥ + iṣṭaḥ + asi + me + dṛḍham + iti + tataḥ + vakṣyāmi + te + hitam

Sanskrit, in depth

The words

देवनागरीWordGrammarSense
सर्व-गुह्यतमम्sarva-guhyatamamaccusative neuterthe most secret of all. --tama (तम) is the superlative, "most."
भूयःbhūyaḥindeclinableagain.
शृणुśṛṇuimperative, 2nd singularhear.
मेmegenitive encliticmy, from me.
परमम्paramamaccusative neutersupreme. Agrees with vacaḥ (वचः).
वचःvacaḥaccusative of vacas (वचस्)word.
इष्टःiṣṭaḥnominativedear, wished-for. Past participle of iṣ (इष्).
असिasipresent, 2nd singularyou are.
मेmegenitive encliticto me.
दृढम्dṛḍhamaccusative adverbfirmly.
इतिitiindeclinablethus. It gives the reason.
ततःtataḥindeclinabletherefore.
वक्ष्यामिvakṣyāmifuture, 1st singularI shall speak. From vac (वच्).
तेtedative encliticto you.
हितम्hitamaccusativewhat is good for you.

The phrases

sarvaguhyatamaṃ bhūyaḥ śṛṇu me paramaṃ vacaḥ (सर्वगुह्यतमं भूयः शृणु मे परमं वचः) reopens the speech 18.63 had closed. Hear again my supreme word, the most secret of all. bhūyaḥ (भूयः) means this is a second telling, past the knowledge already called more secret than the secret.

iṣṭo 'si me dṛḍham iti (इष्टोऽसि मे दृढमिति) is why he will say it. Because you are firmly dear to me. iti (इति) marks that clause as the cause.

tato vakṣyāmi te hitam (ततो वक्ष्यामि ते हितम्) is the promise. Therefore I shall speak to you what is good for you. The speaking is 18.65 and 18.66.

Sanskrit in this line

--tama (तम) is the superlative, one step past the comparative --tara (तर) of guhyataram (गुह्यतरम्) in 18.63. sarva-guhyatamam (सर्व-गुह्यतमम्) is "most secret of all." इष्टः + असि iṣṭaḥ + asi is recited iṣṭo 'si (इष्टोऽसि): अः + अ aḥ + a becomes o (ओ), and the dropped a (अ) of asi (असि) is the avagraha.

Say it back

Cover the English. Say why he will speak again. If iṣṭaḥ (इष्टः) comes out as "you are able," stay here.