। ॥ २१६ ॥
In plain words
Know this, with the subtlest edge of your intellect: there is a knower by which everything else is known, but which is never itself known as an object. That knower is the Self — and it is you.
Close to the Sanskrit
Know, with a very refined intellect, that Self, the knower, by which all [things] are experienced, [but] which itself is never experienced [as an object].