Acts 7:6-8

And God spake on this wise, that his seed should sojourn in a strange land, and that they should bring them into bondage, and treat them ill, four hundred years. And the nation to which they shall be in bondage will I judge, said God: and after that shall they come forth, and serve me in this place. 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 the twelve patriarchs.