Zohar
It is written: "And God said, Let there be light, and there was
light" (Gen. 1, 3). Said R. Jose: 'That light was hidden and kept in
store for the righteous in the world to come, as already stated; for it
is written, "A light is sown for the righteous" (Ps. XCVII, 11).
Thus that light functioned in the world only on the first day of Creation;
after that it was hidden away and no longer seen.' Said R. Judah: 'Had it
been hidden away altogether, the world would not have been able to exist
for one moment. But it was only hidden like a seed which generates others,
seeds and fruits, and the world is sustained by it. There is not a day that
something does not emanate from that light to sustain all things, for it
is with this that the Holy One nourishes the world. Moreover, whenever the
Torah is studied by night, a little thread of this hidden light steals down
and plays upon them that are absorbed in their study, wherefore it is written:
"The Lord commandeth His lovingkindness in the daytime, and in the
night his song is with me" (Ps. XLII, 9); this has already been expounded.
-Zohar II, 148b-149a
