य आकाशे तिष्ठन्नाकाशादन्तरो य-माकाशो न वेद यस्याकाशः शरीरं यआकाशमन्तरो यमयत्येष त आत्मान्त-र्याम्यमृतः ॥ १२ ॥
In plain words
The one who lives inside space itself, yet is nothing space can claim as its own, whom space never knows, whose body space is, who governs it from within -- that is your self, the ruler seated inside everything, and death does not touch him.
Close to the Sanskrit
He who, dwelling in space, is other than space, whom space does not know, whose body space is, who controls space from within -- he is your self, the inner controller, immortal.