Neither do I know, nor do I do not know - Kenopanishad

 

I do not think that I know this well;
nor do I think that I do not know this.
He among us who knows that –
“Neither do I know, nor do I do not know”
-    perceives That well.

Kenopanishad

नाहं मन्ये सुवेदेति नो न वेदेति वेद च ।
यो नस्तद्वेद तद्वेद नो न वेदेति वेद च ॥