Midrasch zu Schemot 12:40

Now the time that the children of Israel dwelt in Egypt was four hundred and thirty years (Exod. 12:40). Yet it is written: And shall serve them, and they shall afflict them four hundred years (Gen. 15:13). Since these two verses are obviously contradictory, how can they be reconciled? The first decree was issued prior to the birth of Isaac, but after Isaac’s birth, the Holy One, blessed be He, reconsidered the matter, as it is said: Thy seed shall be a stranger, and they shall afflict them four hundred years. Abraham reflected on this subject at the time of the decree. It is written: And they shall afflict them four hundred years, but it is also written: In the fourth generation they shall come back hither (ibid., v. 16). How can these verses be reconciled? These verses suggest that, if they repent, I will redeem them after four generations, but if not, after four hundred years. And it came to pass at the end of four hundred and thirty years (Exod. 12:41). At the end of that time he did not delay them as long as the blink of an eye. It was on the fifteenth day of Nisan that he issued the decree and spoke to Abraham our father, at the time of making the covenant-between-the-parts. It was on the fifteenth day of Nisan that ministering angels came to inform him about the birth of Isaac; it was on the fifteenth day of Nisan that Isaac was born; it was on the fifteenth day of Nisan that they were redeemed from Egypt; and it is on the fifteenth day of Nisan that they will be redeemed from servitude to kingdoms. The same day was designated for all these events.

(Exod. 12:40) "Now the time that the children of Israel dwelt in Egypt and in other lands <was four hundred and thirty years>."⁸⁸The emendation tends to agree with the Septuagint, which reads: “in Egypt and in the land of Canaan,” over against the Masoretic Text, which simply reads: “IN EGYPT.” Cf. the parallels in Tanhuma and in Mekhilta, which add “the land of Goshen” to Egypt and Canaan. The reason for the additions is that the Biblical record indicates elsewhere that Israel must have spent far less than four hundred years in Egypt. See Rashi on Exod. 12:40.

And Moses took his wife and his sons, and set them upon an ass (Exod. 4:20). This is one of the ten verses our rabbis altered when they translated the Torah into Greek for King Ptolemy.¹⁶Megillah 9a. The Septuagint, begun during the reign of Ptolemy II Philadelphus (285–246 B.C.E.). The ten changes are: “God created in the beginning” (Gen. 1:1);¹⁷Instead of In the beginning God created, in order to emphasize that God alone created. “I shall make man in My image and My likeness” (ibid., v. 26);¹⁸Instead of Let us make man in our image. etc. “And He finished on the sixth day, and rested on the seventh day (ibid. 2:2);¹⁹Instead of And on the seventh day God finished, thus giving the impression that God actually worked on the seventh day. “Male and female He created him” (ibid. 5:2);²⁰Instead of Male and female He created them, etc. “Come, let Me descend and confound their tongue” (ibid. 11:7);²¹Instead of Come, let us go down, etc. “And Sarah laughed among her relatives” (ibid. 18:12);²²Instead of And Sarah laughed within herself. “For in their anger they slew an ox, and in their wrath they digged up a stall” (ibid. 49:6);²³Instead of For in their anger they slew men, and in their self-will they houghed oxen. “And Moses took his wife and his sons, and made them ride on a carrier of men” (Exod. 4:20);²⁴Instead of… and set them upon an ass. “Now the time that the children of Israel dwelt in Egypt, and in the land of Goshen and in Canaan was four hundred and thirty years” (ibid. 12:40);²⁵Instead of Now the time that the children of Israel dwelt in Egypt was four hundred and thirty years, etc. “And he sent the elect of the children of Israel” (ibid. 24:5);²⁶Instead of And he sent the young men of the children of Israel. “And against the elect of the children of Israel he put not forth his hand (ibid., v. 11);²⁷Instead of And upon the nobles of the children of Israel He laid not His hand. “Since the Lord thy God hath arranged to give light to all the peoples under the entire heavens” (Deut. 4:19);²⁸The words “to give light” were added. “Which I had not commanded the people to serve” (Deut. 17:3);²⁹Instead of Which I have commanded not. they wrote about “the slender-footed,” but they did not write the word ‘arnevet (“the hare”) (Lev. 11:5) because the name of Ptolemy’s wife was ‘Arnevet,³⁰Actually, her name was Arsinoe. and he might say: “The Jews are ridiculing me by writing my wife’s name in the Torah.”

Rabbi Elazar, son of 'Arakh, said to them: The Holy One, blessed be He, said this to Abraham only at the hour when he had seed, as it is said, "Thy seed shall be a stranger in a land that is not theirs" (ibid.). From the time when Isaac was born until Israel went forth from Egypt 400 years (elapsed). (Rabban Jochanan, son of Ẓakkai) said to him: Verily it is written, "Now the sojourning of the children of Israel, which they sojourned in Egypt, was four hundred and thirty years" (Ex. 12:40). He answered him, saying: 210 years Israel abode in Egypt, and five years before Jacob came to Egypt there were born unto Joseph(the fathers of) two tribes, Manasseh and Ephraim, and they belonged to the Israelites. Behold, (we have) 215 years of days and nights, (this equals) 430 years; for the Holy One, blessed be He, reduced the time for the sake of the merit of the Patriarchs, for they are the mountains of the world, and for the sake of the merit of the Mothers, for they are the hills of the world, and concerning them the Scripture says, "The voice of my beloved ! Behold, he cometh, leaping upon the mountains, skipping over the hills" (Cant. 2:8).