Musar do Kapłańska 1:11

Achievement of higher levels of sanctity in the three areas mentioned is all included in the directive to sanctify the body, והתקדשתם. This directive encompasses the entire domain called קומת האדם, "the stature of Man," both its visible and its invisible aspects. The sanctity of space is a mystical dimension of כבוד. The Torah alludes to this when it legislates that most sacrifices have to be offered on the northern side of the altar. Whenever that term is used in the Torah, it is associated with the words: לפני ה', "in the presence of the Lord." In other words, G–d is perceived as being צפונה. [The deeper meaning of the word is clearly related to the word צפון, "hidden." Ed.] I have dealt with this concept at length when I wrote about the statement in Shir Hashirim Rabbah 7,6 that "as long as an embryo is within its mother's womb it receives all its sustenance through its navel."