Why does the Torah write, "va'Yakam Melech Chadash" (and not 'va'Yimloch')?
Rashi and Targum Yonasan: This is why (according to some opinions 1 - Rashi) it was not a new king at all. It was the same king, who really knew Yosef, but who adopted a new attitude 2 towards Yisrael. 3
Oznayim la'Torah: Assuming it was the same Pharaoh as before, the Torah uses this expression because he had been king before as well - but in name only. Pharaoh had appointed Yosef the de facto ruler of Egypt, "v'Nason Oso Al Kol Eretz Mitzrayim" (Bereishis 41:43), while Pharaoh remained king in name only. Now, Pharaoh 'arose' to adopt a new role as ruler of Egypt. 4
Rashi: This is actually a Machlokes between Rav and Shmuel in Sotah 11a.
Sotah 11a: As if he did not know Yosef.
Da'as Zekenim: Initially, Pharaoh refused to afflict Yisrael, and [the people] deposed him. After three months, he consented, and "Va'Yakam" - he was reinstated.
Oznayim la'Torah: Which also explains the Torah's use of the words "Al Mitzrayim" rather than 'b'Mitzrayim.'
According to those who explain "Melech Chadash" literally, why does the Torah need to mention the fact that he did not know Yosef?
Seforno: Yosef was certainly mentioned in the chronicles of Egypt - particularly with regard to the new laws that he initiated- in which case the new king ought to have treated the people to which Yosef belonged favorably. However, it did not occur to him that Yosef had any connections with Bnei Yisrael.
Targum Onkelos: It means that he discarded the laws that Yosef initiated. 1
See also Targum Yonasan, Perush Yonasan and Na'ar Yonasan.
QUESTIONS ON RASHI
Rashi writes: "'A new king arose' - [This is a dispute between] Rav and Shmuel (Eruvin 53a) - one says he was actually new; the other says his decrees became new." The first opinion is based on the word "new;" but even so, it would suffice to say, 'A king arose over Egypt'!
Gur Aryeh: To this opinion, what the Pasuk is telling us is that this new ruler was not the son of the previous king, nor in any way his continuation. Rather, he began a new dynasty. That is why he initiated evil decrees. (Also refer to 1:8:1.3:1).
Rashi writes: "... Rav and Shmuel; one says [the king] was actually new; the other says his decrees became new." What is behind this Machlokes?
Gur Aryeh: The first opinion says that had the new Pharaoh been from the previous dynasty (of Yosef's times), he would never have made such decrees. That is why Hashem removed the old dynasty, and established a new one. To the second view, [this was unnecessary, because ultimately,] the decree of slavery was from Hashem.
Rashi writes: "... The other opinion says his decrees became new." Was it then the same person? How could it be that this wicked Pharaoh lived for so long!?
Gur Aryeh: We need not say that he was the same person! To this second view, this Pharaoh was the son of the previous king, and a continuation of the same dynasty. When a son succeeds his father to the throne, it is as if they were one king.
