Sefer HaSichos 5752 page 280 ff.
This class (only) introduces this Sicha: there is a pattern to how Hashem has Moshe visit the Pharaoh. The first (fourth and seventh) he tells him לך… go to the Pharoh at the River. The second (fifth and eighth) he tells him בא… go see him in the palace. The Third (sixth and ninth) there...
Continued (2). Moshe fears the spiritual evil of Pharaoh which is above קדושה!
Continued (3). Moshe fears the positive spiritual Pharaoh as well. Why?