(ח) וַיָּקָם מֶלֶךְ חָדָשׁ עַל מִצְרָיִם אֲשֶׁר לֹא יָדַע אֶת יוֹסֵף.
וַיָּקָם מֶלֶךְ חָדָשׁ
A new king arose: [There is a controversy between] Rav and Samuel. One says: He was really new, and the other one says: His decrees were new. [From Sotah 11a, Exod. Rabbah 1:8] Since the Torah does not say: The king of Egypt died, and a new king arose, it implies that the old king was still alive, only that his policies had changed, and he acted like a new king.
Rashi on Sotah 11a
How could the Egyptian Pharaoh who stretched back to the days of Yosef not know Yosef? Yosef saved his country and the entire world from famine, both by interpreting the dreams of Pharaoh and by managing the collection of funds for the years of famine. Yosef singlehandedly made Pharaoh the most wealthy and powerful personality on the planet. How can he not know who Yosef is?
Rashi answers that he made himself as if he did not know Yosef. His behavior to the Jewish people could only have been as brutal as it was if the king willfully blinded himself. He was able to deny the good that Yosef had done in order to permit himself to be cruel to his family. This is the trick Pharaoh played on himself. That self-deception brought him to an even greater delusion. In the end he makes the outrageous remark, “Who is HASHEM that I should heed His voice?”
Rabbi Label Lam 2007
Although there was certainly a record of Joseph's accomplishments in the annals of the kings.....nonetheless, the new king could not believe that Joseph could have been a member of the same people so that Israel could be worthy on his account.
Rabbi Ovadia Sforno
Heb. הָבָה. Every הָבָה [found in the Torah] is an expression of preparation and readiness. That is to say: Prepare yourselves for this.
"Let us deal wisely with them” With the people [of Israel]. Let us act shrewdly regarding what to do to them. Our Rabbis, however, interpreted [that Pharaoh said], Let us deal shrewdly with the God of Israel [thus interpreting לוֹ as to him] by afflicting them [to die] with water, for He has already sworn that He would not bring a flood to the world. (But they [the Egyptians] did not understand that upon the whole world He would not bring [a flood] but He would bring it upon one nation
"and depart from the land" against our will. Our Rabbis, however, interpreted [i. e., depicted Pharaoh] as a person who curses himself but ascribes his curse to others. And it is as if it were written: and we will depart from the land, and they will take possession of it.
Rabbi Ovadia Sforno
הָאַחַת שִׁפְרָה- This is Yocheved, because she beautifies the children at birth. (she washed and cleaned the infants at birth). The word הָאַחַת indicates who was first or in charge. In this case it was the mother Yocheved.
הַשֵּׁנִית פּוּעָה - This is Miriam, because she soothed the crying babies. The word הַשֵּׁנִית indicates that she was inferior in stature to her mother.
Rashi