Read until the end, you will have your answer. May the Most High Bless you
The bile didn't say that Israelites would be in captivity for 400 yrs. From the beginning to the Exodus you could not get 400 yrs. Genesis 15:13 Know for a surety that thy seed should be a stranger in a land that is not theirs and shall serve then and shall afflict the 400 yrs. His seed was Isaac and it expound to Jacob, this wasn't talking about captivity in Egypt. God was sending the Israelites into Egypt to get the substance needed to prepare them for the promise land.
Genesis 15:16 but in the 4th generation, they shall come hither gain for the iniquities of the Ammorites is not yet full.----You cannot get 400 years from the 4th generation of Abraham. Exodus 12:41 All of the children of Israel left Egypt at the end of 430 years. The law came 430 years after the promise that God gave Abraham unto the Exodus. Galatians 3:15-17 Brethren, I speak after the manner of men; Though it be but a man's covenant, yet if it be confirmed, no man disannulleth, or addeth thereto.
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
In the Septuagint original text book of Exodus 12:40 And the sojourning of the children of Israel, while they sojourned in the land of Egypt and the land of Chanaan, was four hundred and thirty years. SEE, the 430 years was over a period of time that they lived in the land. In the new translation, they left out "and in the land of Canaan".
The book of Josephus Book 2 Chapter 15 para 2 2. They left Egypt in the month Xanthicus, on the fifteenth day of the lunar month; four hundred and thirty years after our forefather Abraham came into Canaan, but two hundred and fifteen years only after Jacob removed into Egypt. (28) It was the eightieth year of the age of Moses, and of that of Aaron three more. They also carried out the bones of Joesph with them, as he had charged his sons to do.