The System of the Vedanta according to Badarayana's Brahma-Sutras and Cankara's Commentary c6.s5.t2.7

c6.s5.t2.7

"Therefore, verily, that which is called Brahman, that is certainly that which this space outside the man is; but the space which is outside the man is certainly that which this space inside the man is; but this space inside the man is certainly that which this space inside the heart is: this is that Perfect, Unchangeable [a definition, which Bṛh. 2, 1, 5 is found to be inadequate]; perfect, unchangeable happiness he gains, who knows this."