। ॥ ८७३ ॥
In plain words
Even the thing you see is only witnessed by the Self. So the state in which the mind lets go of the very figuring it had been holding up in the Self — that state is called nirvikalpa, absorption with nothing framed in it.
Close to the Sanskrit
And because even of the seen there is witness-hood, that state of mind which removes the explicit figuring in the Self is called nirvikalpa.