By which makkah did Pharaoh have flashbacks of little Moshe growing up in his palace?
At the height of the plague of Grasshoppers, Pharaoh calls Moshe and Aharon to come to him (10:16). Then he says "please forgive me (singular, talking to only person) – “and please daven to HaShem for me” (plural, referring to both Moshe and Aharon) (10:17). The Keli Yakar explains that the individual who was asked for forgiveness here is referring to Aharon and not Moshe. Pharaoh remembered Moshe growing up in his palace, and was well aware of his sterling character and humility. Pharaoh knew that Moshe immediately would forgive anyone causing him pain, so he did not even bother to ask him for forgiveness. Since Pharaoh did not know Aharon that well, he therefore had to ask him straight out if he would forgive him.
Which element from the plague of Grasshoppers was used in the plague of Darkness?
The plague of Darkness came about through a heavy cloud that descended upon the Egyptians. This mist was formed from the Western wind that carried the Grasshoppers away (10:19} (Abarbanel).
Others learn that the plague of Darkness was a plague that affected the eyes of the Egyptians, and thus temporarily blinded their eyesight (producing a feeling of Darkness) (Hakesav Vehakabbalah).
