Rabbi Yosi says that it is necessary to be occupied with the Torah day and night, and that one must rise after midnight to study Torah because it is then that the Holy One, blessed be He, enters into the Garden of Eden to delight Himself with the righteous there. He draws a thread of kindness during the day for those who occupy themselves with Torah in the night.
Rabbi Yitzchak talks about "And Hashem went before them by day," saying that the Shechinah traveled with the Patriarchs - Abraham, Isaac, Jacob and King David. They are all the Holy Chariots of above. The people traveled day and night when they left Egypt, so that they would be complete with everything, night and day together - the aspect of Zeir Anpin and the aspect of Nukva. The "pillar of cloud" was Chesed, Abraham, and the "pillar of fire" was Gvurah, Isaac, so that Yisrael was illuminated by day and by night. Again we are told of the fifty days' delay after their redemption from Egypt before they received the Torah at Mount Sinai. Then the fifty days of Jubilee, the fifty gates of Binah, dwelled upon them. Rabbi Yitzchak says that the Pharaoh's wise men and sorcerers, who saw that Yisrael were traveling by day and by night, told him that the people had fled.