कच्चिदेतच्छ्रुतं पार्थ त्वयैकाग्रेण चेतसाकच्चिदज्ञानसम्मोहः प्रनष्टस्ते धनञ्जय
In plain words
Partha, have you heard this with a one-pointed mind? Has your delusion born of ajñāna been destroyed, Dhananjaya?
Word for word
Has this been heard by you, O son of Pṛthā, with a one-pointed mind? Has your delusion born of ignorance been destroyed, O Dhanañjaya?
The commentators
Bhagavadgītābhāṣyam
शिष्यस्य शास्त्रार्थग्रहणाग्रहणविवेकबुभुत्सया पृच्छति । तदग्रहणे ज्ञाते पुनः ग्राहयिष्यामि उपायान्तरेणापि इति प्रष्टुः अभिप्रायः । यत्नान्तरं च आस्थाय शिष्यस्य कृतार्थता कर्तव्या इति आचार्यधर्मः प्रदर्शितो भवति —
कच्चित् किम् एतत् मया उक्तं श्रुतं श्रवणेन अवधारितं पार्थ, त्वया एकाग्रेण चेतसा चित्तेन ? किं वा अप्रमादतः ? कच्चित् अज्ञानसंमोहः अज्ञाननिमित्तः संमोहः अविविक्तभावः अविवेकः स्वाभाविकः किं प्रणष्टः ? यदर्थः अयं शास्त्रश्रवणायासः तव, मम च उपदेष्टृत्वायासः प्रवृत्तः, ते तुभ्यं हे धनञ्जय ॥ ७२ ॥
In plain words
He asks this simply to find out whether Arjuna has truly understood the teaching or not. His intention: 'if I find he hasn't grasped it, I will teach it to him again, even by another approach if needed.' In being ready to make this further effort, to see that the disciple's purpose is actually fulfilled, we see here exactly what a teacher owes a student —
Have you heard this teaching, Pārtha, truly taken it in, listened with a gathered, undistracted mind, attentively, without slipping? I hope so. And I hope the confusion that came from not-knowing — that natural bewilderment, that lack of clear seeing — has now been dispelled in you. Because that is exactly why you made this effort to listen, and why I made this effort to teach: for this, Dhanañjaya.
Close to the Sanskrit
He asks out of a desire to discern whether the meaning of the teaching has been grasped by the disciple or not. 'Once it is known that it has not been grasped, I will cause [him] to grasp it again, even by another means' — this is the questioner's intention. And, by resorting to a further effort, the accomplishment of the disciple's purpose is to be brought about: thus the duty of a teacher is [here] exemplified —
I hope this has been spoken, heard by hearing, ascertained by you, O son of Pṛthā, with a one-pointed mind — with attention? Or [I hope it was heard] without negligence? I hope the confusion born of ignorance — the confusion occasioned by ignorance, the state of non-discrimination, the lack of discrimination, [your] natural [confusion] — has been destroyed? For the purpose of which this effort of hearing the teaching was [made] by you, and the effort of teaching was undertaken by me, to you, O Dhanañjaya.