The 400 Year Prophecy Mystery Explained

The 400 years prophecy to Abraham doesn’t seem to fit the details mentioned in the Torah. This blog is to explain the problem and provide a plausible solution only using authoritative texts.

(Gen 15:8,13-16) And he said, “Lord GOD, how shall I know that I will inherit it?” …  Then the LORD said to him, “Know for certain that for four hundred years your descendants will be strangers in a country not their own and that they will be enslaved and mistreated there. But I will punish the nation they serve as slaves, and afterward they will come out with great possessions. You, however, will go to your ancestors in peace and be buried at a good old age. In the fourth generation your descendants will come back here, for the sin of the Amorites has not yet reached its full measure.” 

Acts 7:6 “But God spoke in this way: that his descendants would dwell in a foreign land, and that they would bring them into bondage and oppress them four hundred years

Based on the above verses, the total time the children of Israel in Egypt was 400 years. If we do so, we quickly run into some big problems if we take the details mentioned in the Torah.
Jacob went to Egypt when he was 130 years old which is 191 years after the birth of Isaac. Adding 400 years must be the beginning of Exodus where Moses must be 80 years old. However, if we go by the detailed years of birth mentioned in the law, we notice that Levi died 93 years after Jacob came to Egypt. Levi’s son is Kohath and Kohath’s son is Amram and Amram’s son is Moses. Further, Jochebed is Levi’s daughter who is also Moses’s mother. Based on Genesis 46, Kohath came with Jacob to Egypt and Levi was 44 years old at that time, which will make Kohath a boy of roughly around 10 years old when he left for Egypt with his father Levi. Hence, Kohath must have been around 103 years old when Levi died and he lived till 133 years, i.e, a further 30 years. Amram lived 137 years. The 400 year prophecy ends when Amram’s son Moses becomes 80 years old. Did you see the problem? I will represent it in a pictorial way to better understand the issue.
Even if Amram was born on the year Kohath died and Moses was born on the year Amram died, we still have to tally 50 years! However, as the prophecy says, Moses is exactly 4th generation to Jacob who left for Egypt but the 400 years doesn’t fit unless, we completely misunderstood the prophecy itself.

Gen 15:3 Then Abram said, “Look, You have given me no offspring; indeed one born in my house is my heir!” … 5 Then He brought him outside and said, “Look now toward heaven, and count the stars if you are able to number them.” And He said to him, “So shall your descendants be.” … 13-16 Then the LORD said to him, “Know for certain that for four hundred years your descendants will be strangers in a country not their own and that they will be enslaved and mistreated there. But I will punish the nation they serve as slaves, and afterward they will come out with great possessions. You, however, will go to your ancestors in peace and be buried at a good old age. In the fourth generation your descendants will come back here, for the sin of the Amorites has not yet reached its full measure.”

If you look into the prophecy in carefully, the 400 years begins with his promised son Isaac who was his first descendant heir to the promised land, who living as a stranger in the land. Hence, from the birth of Isaac to the beginning of Exodus are 400 years.