यो दिक्षु तिष्ठन् दिग्भ्योऽन्तरो यं दिशो न विदुर्यस्य दिशः शरीरं यो दिशोऽन्तरो यमयत्येष त आत्मान्तर्याम्यमृतः ॥३,७.१० ॥
In plain words
He who dwells in the quarters, yet is within the quarters, whom the quarters do not know, whose body the quarters are, who from within controls the quarters — he is thy Self, the inner controller, the immortal.