In plain words
I know all beings that have passed, those present, and those yet to come, Arjuna; but no one knows Me.
Word for word
I know the past and present beings, O Arjuna, and the future ones; but Me no one knows.
वेदाहं समतीतानि वर्तमानानि चार्जुनभविष्याणि च भूतानि मां तु वेद न कश्चन
Other commentaries
The commentators
▸Bhagavadgītābhāṣyam
यतः एवम् , अतः —
अहं तु वेद जाने समतीतानि समतिक्रान्तानि भूतानि, वर्तमानानि च अर्जुन, भविष्याणि च भूतानि वेद अहम् । मां तु वेद न कश्चन मद्भक्तं मच्छरणम् एकं मुक्त्वा ; मत्तत्त्ववेदनाभावादेव न मां भजते ॥ २६ ॥
In plain words
Since this is how it stands, therefore —
But I know them: the beings already gone, gone completely by; the beings alive right now, Arjuna; and the beings still to come — those too I know. Me, though, no one knows. No one, except the one who is devoted to me and has made me his refuge. Because the knowledge of what I actually am is simply not there, a person does not turn to me at all.
Close to the Sanskrit
Since (it is) thus, therefore —
But I know — I am aware of — beings wholly gone by, that is, wholly passed away, and those existing now, O Arjuna, and beings yet to come I know, I. But me no one knows, excepting that one alone who is my devotee, who has me for his refuge; precisely from the absence of the knowing of my true nature, he does not worship me.