Why was Paroah made King in Ninveh?

(16) Nevertheless I have spared you for this purpose: in order to show you My power, and in order that My fame may resound throughout the world.

(8) Rabbi Nechunia, son of Haḳḳanah, said: Know thou the power of repentance. Come and see from Pharaoh, king of Egypt, who rebelled most grievously against the Rock, the Most High, as it is said, "Who is the Lord, that I should hearken unto his voice?" (Ex. v. 2). In the same terms of speech in which he sinned, he repented, as it is said "Who is like thee, O Lord, among the mighty?" (ibid. xv. 11). The Holy One, blessed be He, delivered him from amongst the dead. Whence (do we know) that he died? Because it is said, "For now I had put forth my hand, and smitten thee" (ibid. ix. 15). He went and ruled in Nineveh. The men of Nineveh were writing fraudulent deeds, and everyone robbed his neighbour, and they committed sodomy, and such-like wicked actions. When the Holy One, blessed be He, sent for Jonah, to prophesy against (the city) its destruction, Pharaoh hearkened and arose from his throne, rent his garments and clothed himself in sackcloth and ashes, and had a proclamation made to all his people, that all the people should fast for two days, || and all who did these (wicked) things should be burnt by fire. What did they do? The men were on one side, and the women on the other, and their children were by themselves; all the clean animals were on one side, and their offspring were by themselves. The infants saw the breasts of their mothers, (and they wished) to have suck, and they wept. The mothers saw their children, (and they wished) to give them suck. By the merit of 4123 children more than twelve hundred thousand men (were saved), as it is said, "And should not I have pity on Nineveh, that great city; wherein are more than six score thousand persons that cannot discern between their right hand and their left hand; and also much cattle?" (Jonah iv. 11); "And the Lord repented of the evil, which he said he would do unto them" (ibid. iii. 10). For forty years was the Holy One, blessed be He, slow to anger with them, corresponding to the forty days during which He had sent Jonah. After forty years they returned to their many evil deeds, more so than their former ones, and they were swallowed up like the dead, in the lowest Sheol, as it is said, "Out of the city of the dead they groan" (Job xxiv. 12).

(51) Keeping this in mind, we understand that when Pharaoh said: לא כן (10,11) he rejected this concept and heaped a curse on himself instead. He actually said: ראו כי רעה נגד פניכם, "I see destruction facing you." At that moment the מלאך רע, the "evil" angel, speaking through Pharaoh's mouth, responded against his better judgment: לא כן, "not so," i.e. the blood which Pharaoh believed to be facing Israel, and which he interpreted as a sign of Israel's defeat in battle, would be turned into the blood of circumcision and have a beneficial effect on Israel. Although this was not what Pharaoh intended when he said these words, this is only one of many instances when man utters something while unaware of the far-reaching effect of his words. The words spoken in such cases are really G–d's words.

(52) I have found a similar interpretation in a book called כנפי יונה, chapter 68. Concerning the verse: ל"א כ"ן ראו כי ראה נגד פניכם,the author states that the numerical value of the high-lighted words is the same as that of the names of the angel מיכאל =101. The angel Michael happened to have been present at that moment of Moses' meeting with Pharaoh, and he placed words into Pharaoh's mouth which effectively neutralised the curse contained in the words immediately prior to לא כן. This meant in effect that Pharaoh, i.e. the "evil" angel, was now transformed into a messenger of the angel Michael. The numerical value of the seven words starting with ראו, amounts to a total of 870. Ten times the name א-להים plus the letter י from the name מיכאל total 870. The words: ברכת אברהם also total 870. We therefore see that by adding the words לא כן to the previous curse of: רשאו כי רעה נגד פניכם, the curse of Pharaoh was changed into the blessing of Abraham, i.e. the blessing implied in fulfilling the commandment of circumcision. Thus far the author of כנפי יונה.