50. As for the eyes of the head of Atika Kadisha, WHICH IS ARICH ANPIN, both EYES are as one. They constantly observe and never sleep, as it is written, "Behold, He who keeps Yisrael shall neither slumber nor sleep" (Tehilim 121:4), which refers to holy Yisrael, ZEIR ANPIN. For that reason He has neither eyebrows nor eyelids.
141. The eyebrows are never lying over the eyes except when the white colors wish to observe, because the eyebrows give all colors room to observe. If they do not, no COLOR can supervise and watch. The eyebrows do not stand IN ONE PLACE and never lie still for a whole hour, but open and close, close and open, since the observing eye is over them. Hence it is written, "And the living creatures ran and returned" (Yechezkel 1:14). I have already explained this.