Midrash Rabbah Beresheet on the Ascent and Descent of Shekhinah

"Originally, the place of the Shekhinah was in the lower regions. When Adam sinned it ascended to the first heaven; when Cain sinned it ascended to the second heaven; in the generation of Enoch it ascended to the third; in the generation of the Flood to the fourth; in the generation of the Tower of Babel to the fifth; the men of Sodom caused it to depart to the sixth; and the Egyptians in the time of Abraham caused it to depart to the seventh. In contradistinction, seven righteous men arose and made it descend. Abraham brought it down to the sixth, Isaac to the fifth, Jacob to the fourth, Levi to the third, Kohath to the second, Amram to the first, and Moses caused it to come down from above to below on earth."

-- Midrash Rabbah, Beresheet 19.7