The common belief is that the Hebrews were slaves in Egypt 430 years. This is based on Exodus 12:40 "Now the sojourning of the children of Israel, who dwelt in Egypt, was four hundred and thirty years." (KJV)

However, this can also be read as: Now the wandering of the children of Israel, who now dwelt in Egypt, was four hundred and thirty years. In other words, ever since Abraham had left his home in Haran, he and his decedents had no land they could call their own. They were not a nation and wandered throughout Canaan and Egypt subject to the government of whatever land they were in.

Using the genealogies given in the books of Genesis and Exodus, it is relatively easy to trace time back four hundred and thirty years from the Exodus. This takes us to the exact time that Abraham left his home in Haran . . . . exactly four hundred and thirty years before the decedents of Abraham came out of Egypt as the newly born nation of Israel!

This is further confirmed in Genesis 14:13 when God reminds Abraham of the covenant saying "thy seed shall be a stranger in a land that is not theirs, and shall serve them; and they shall afflict them four hundred years." Note that God says four hundred years (in contrast to the four hundred and thirty years in Exodus 12:40). This is because twenty five years had passed since Abraham left Haran, now leaving four hundred and five years to the Exodus. So the children of Abraham (Jacob's family) were in Egypt two hundred and thirty-seven years, not four hundred and thirty years as commonly believed.

Exod 12:40 Now the of the children of Israel, who dwelt in Egypt, was four hundred and thirty years. 41 And it came to pass at the end of the four hundred and thirty years, even the selfsame day it came to pass, that all the hosts of the LORD went out from the land of Egypt. (KJV)

Gen 12:1 Now the LORD had said unto Abram, Get thee out of thy country, and from thy kindred, and from thy father's house, unto a land that I will shew thee: 2 And I will make of thee a great nation, and I will bless thee, and make thy name great; and thou shalt be a blessing: 3 And I will bless them that bless thee, and curse him that curseth thee: and in thee shall all families of the earth be blessed. 4 So Abram departed, as the LORD had spoken unto him; and Lot went with him: and Abram was seventy and five years old when he departed out of Haran. (KJV)

Gen 15:13 And he said unto Abram, Know of a surety that thy seed shall be a stranger in a land that is not theirs, and shall serve them; and they shall afflict them four hundred years; 14 And also that nation, whom they shall serve, will I judge: and afterward shall they come out with great substance. 15 And thou shalt go to thy fathers in peace; thou shalt be buried in a good old age. 16 But in the fourth generation they shall come hither again: for the iniquity of the Amorites is not yet full. 17 And it came to pass, that, when the sun went down, and it was dark, behold a smoking furnace, and a burning lamp that passed between those pieces. 18 In the same day the LORD made a covenant with Abram, saying, Unto thy seed have I given this land, from the river of Egypt unto the great river, the river Euphrates: (KJV)

Acts 7:2 And he said, Men, brethren, and fathers, hearken; The God of glory appeared unto our father Abraham, when he was in Mesopotamia, before he dwelt in Charran, 3 And said unto him, Get thee out of thy country, and from thy kindred, and come into the land which I shall shew thee. 4 Then came he out of the land of the Chaldaeans, and dwelt in Charran: and from thence, when his father was dead, he removed him into this land, wherein ye now dwell. 5 And he gave him none inheritance in it, no, not so much as to set his foot on: yet he promised that he would give it to him for a possession, and to his seed after him, when as yet he had no child. 6 And God spake on this wise, That his seed should sojourn in a strange land; and that they should bring them into bondage, and entreat them evil four hundred years. 7 And the nation to whom they shall be in bondage will I judge, said God: and after that shall they come forth, and serve me in this place. 8 And he gave him the covenant of circumcision: and so Abraham begat Isaac, and circumcised him the eighth day; and Isaac begat Jacob; and Jacob begat the twelve patriarchs. (KJV)

Gal 3:16 Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ. 17 And this I say, that the covenant, that was confirmed before of God in Christ, the law, which was four hundred and thirty years after, cannot disannul, that it should make the promise of none effect. (KJV)