In plain words
I shall tell you this jñāna together with vijñāna, completely; once it is known, nothing further remains here to be known.
Word for word
This jñāna together with vijñāna I shall tell to you completely, having known which nothing else remains here further to be known.
ज्ञानं तेऽहं सविज्ञानमिदं वक्ष्याम्यशेषतःयज्ज्ञात्वा नेह भूयोऽन्यज्ज्ञातव्यमवशिष्यते
Other commentaries
The commentators
▸Bhagavadgītābhāṣyam
तच्च मद्विषयम् —
ज्ञानं ते तुभ्यम् अहं सविज्ञानं विज्ञानसहितं स्वानुभवयुक्तम् इदं वक्ष्यामि कथयिष्यामि अशेषतः कार्त्स्न्येन । तत् ज्ञानं विवक्षितं स्तौति श्रोतुः अभिमुखीकरणाय — यत् ज्ञात्वा यत् ज्ञानं ज्ञात्वा न इह भूयः पुनः अन्यत् ज्ञातव्यं पुरुषार्थसाधनम् अवशिष्यते नावशिष्टं भवति । इति मत्तत्त्वज्ञो यः, सः सर्वज्ञो भवतीत्यर्थः । अतो विशिष्टफलत्वात् दुर्लभं ज्ञानम् ॥ २ ॥
In plain words
And that is about me —
I am going to tell you this knowledge completely, Arjuna — not just the theory but the lived realization behind it too, drawn from your own direct experience. Nothing held back. Before he even begins teaching it, Kṛṣṇa is praising it, simply to turn Arjuna's whole attention toward what's coming. And here's why it deserves that praise: once you know this, there is nothing else left in this world that still needs knowing, nothing further that could still serve you on the way to what you're really after. Which means whoever comes to know the truth of who I am becomes, in that very act, someone who knows everything. That's exactly why this knowledge is so rare — because what it gives you is nothing less than that.
Close to the Sanskrit
And that (is) having-me-as-its-object —
To you, to you, I shall tell, shall relate, this knowledge together with realization, accompanied by realization, endowed with your own direct experience, completely, in its entirety. That knowledge, about to be taught, [Kṛṣṇa] praises, for the purpose of turning the listener's attention toward it — having known which, having known which knowledge, nothing further, again, other, to be known, a means to the goal of human life, remains, does not remain, is. Thus, one who is a knower of My truth, he becomes all-knowing; that is the meaning. Therefore, because of having such an exceptional result, this knowledge is rare.