सिद्धिं प्राप्तो यथा ब्रह्म तथाप्नोति निबोध मे। समासेनैव कौन्तेय निष्ठा ज्ञानस्य या परा ॥

siddhiṁ prāpto yathā brahma tathāpnoti nibodha me samāsenaiva kaunteya niṣhṭhā jñānasya yā parā

How he who hath attained perfection obtaineth the Eternal, that highest state of wisdom, learn thou from Me only succinctly, O Kaunteya.

In plain words: Krishna tells Arjuna he will briefly explain how a person who has reached perfection goes on to reach the Eternal, the highest state of wisdom.