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.

1. God chose His words carefully. The descendants of Abraham would dwell on other people's land for 400 years. It would be a long time before anyone actually "inherits" the promised land.

2. 400 years was mentioned in Genesis 15:13. A more precise number is given in Exodus 12:40; Galatians 3:17 also says that it was 430 years.

3. There is no contradiction. They, like we do, often used round numbers. We might say the Civil War was 150 years ago, when actually 2006 - 1861 = 145 years. 400 is a round number. 430 is a precise number.

4. One other matter is when to start counting. Do you count only the time in Egypt? Do you begin counting when Abraham left Haran for the land of Caanan? Do you start counting when Joseph went to Egypt or when all the family of Jacob moved to Egypt?