Bhagavad Gita 4.2

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

evaṃ paramparāprāptamimaṃ rājarṣayo viduḥ |sa kāleneha mahatā yogo naṣṭaḥ parantapa ||

This, handed down in regular succession by the royal sages, was known. This Yoga, however, has been lost here over time, O Parantapa (burner of the foes).

The Divine Kings knew it, for it was their tradition; then, after a long time, it was at last forgotten.

Our plain-language meaning of this verse is waiting for scholar review.