Acts 7:6

But God spoke to this effect, that his descendants would be aliens in a foreign land, and that they would be enslaved and mistreated for four hundred years.

Galatians 3:17

What I mean is this: the Law, which came four hundred and thirty years later, does not invalidate a covenant previously ratified by God, so as to nullify the promise.

Treasury of Scripture Knowledge

Summary

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.

Bible References

Four

Galatians 3:17
What I mean is this: the Law, which came four hundred and thirty years later, does not invalidate a covenant previously ratified by God, so as to nullify the promise.