4.2

एवं परम्पराप्राप्तमिमं राजर्षयो विदुः ।
स कालेनेह महता योगो नष्टः परन्तप ॥

evaṃ paramparāprāptam imaṃ rājarṣayo viduḥ
sa kālena iha mahatā yogo naṣṭaḥ parantapa

Kṛṣṇa (कृष्ण) is still speaking, to Arjuna.

The verse

The royal seers knew this yoga, received in succession, and by a long time it was lost here, scorcher of the foe.

नेपालीमा

राजर्षिहरूले परम्पराबाट पाएको यो योग जानेका थिए। धेरै समय बित्दा यो यहाँ हरायो, हे शत्रुलाई पोल्ने।

Where it sits

4.1 built the line, and this verse breaks it: the yoga Arjuna is about to hear is the same one, after the succession failed. The next verse will say why it is being said again, and to whom.

Split: एवम् + परम्परा-प्राप्तम् + इमम् + राज-ऋषयः + विदुः + सः + कालेन + इह + महता + योगः + नष्टः + परन्तप

evam + paramparā-prāptam + imam + rāja-ṛṣayaḥ + viduḥ + saḥ + kālena + iha + mahatā + yogaḥ + naṣṭaḥ + parantapa

Sanskrit, in depth

The words

देवनागरीWordGrammarSense
एवम्evamindeclinablethus. In the way 4.1 just said.
परम्परा-प्राप्तम्paramparā-prāptamaccusative singularreceived in succession. paramparā (परम्परा) is the line from one to the next. prāpta (प्राप्त) is "reached, received."
इमम्imamaccusative singularthis. The same yoga.
राज-ऋषयःrāja-ṛṣayaḥnominative pluralthe royal seers. rāja (राज) plus ṛṣi (ऋषि).
विदुःviduḥperfect, 3rd pluralthey knew. From vid (विद्).
सःsaḥnominativethat. Points ahead to yogaḥ (योगः).
कालेनkālenainstrumental singularby time.
इहihaindeclinablehere. In this world.
महताmahatāinstrumental singularby a great one. Agrees with kālena (कालेन).
योगःyogaḥnominativethe yoga.
नष्टःnaṣṭaḥnominativelost, perished. From naś (नश्).
परन्तपparantapavocativescorcher of the foe. para (पर) is the foe, tapa (तप) the scorching. Arjuna.

The phrases

एवं परम्पराप्राप्तम् इमम् राजर्षयः विदुः evaṃ paramparāprāptam imaṃ rājarṣayaḥ viduḥ is who still had it. The royal seers knew this yoga, received the way 4.1 described. अ + ऋ a + ṛ inside the compound is ar (अर्): rājarṣayaḥ (राजर्षयः). Before the voiced v (व्) of viduḥ (विदुः), aḥ (अः) becomes o (ओ): rājarṣayo viduḥ (राजर्षयो विदुः).

saḥ kālena iha mahatā yogaḥ naṣṭaḥ (सः कालेन इह महता योगः नष्टः) is the loss. That yoga was lost here by a long time. kālena (कालेन) and mahatā (महता) are both instrumental. One is the means, the other describes it. अ + इ a + i joins kālena (कालेन) and iha (इह) into kāleneha (कालेनेह). yogaḥ naṣṭaḥ (योगः नष्टः) is recited yogo naṣṭaḥ (योगो नष्टः).

parantapa (परन्तप) is Arjuna, named by what a fighter does. The vocative does not change the grammar of naṣṭaḥ (नष्टः).

Sanskrit in this line

aḥ (अः) before a voiced consonant becomes o (ओ). rājarṣayaḥ viduḥ (राजर्षयः विदुः) is rājarṣayo viduḥ (राजर्षयो विदुः), and yogaḥ naṣṭaḥ (योगः नष्टः) is yogo naṣṭaḥ (योगो नष्टः). The pronoun saḥ (सः) is the exception in this same verse. Before a consonant it is recited sa (स), not so (सो). sa kālena (स कालेन) is saḥ kālena (सः कालेन).

Say it back

Who knew it, and what time did to it. If naṣṭaḥ (नष्टः) comes out as "hidden for a while," stay here. The verse says it was lost.