And he said unto Abram, Know of a surety that thy seed shall be a stranger in a land that is not theirs, and shall serve them; and they shall afflict them four hundred years;
God speaks to Abram about the future of his descendants in a vision.
Genesis 15:13
King James Version (public domain)
Traditionally attributed to Moses · c. 13th century BC · The Pentateuch — Genesis, Exodus, Leviticus, Numbers, and Deuteronomy — is traditionally attributed to him
Context
11And when the fowls came down upon the carcases, Abram drove them away.
12And when the sun was going down, a deep sleep fell upon Abram; and, lo, an horror of great darkness fell upon him.
13And he said unto Abram, Know of a surety that thy seed shall be a stranger in a land that is not theirs, and shall serve them; and they shall afflict them four hundred years;
14And also that nation, whom they shall serve, will I judge: and afterward shall they come out with great substance.
15And thou shalt go to thy fathers in peace; thou shalt be buried in a good old age.