זוהר בראשית — דף ריב ע”ב

The Holy One blessed be He established Joseph in Egypt. The serpent rebelled against him but could not prevail. The great serpent is Samael, the prince of Egypt. The Holy One blessed be He found a side path to save Joseph from the serpent's hands. And when Joseph fell into Egypt's hands, the Shekhinah never abandoned him for even one hour.