Genesis 15:13

a stranger The word used (gêr) (LXX πάροικος) means more than a "sojourner" (cf. Genesis 23:4; Exodus 2:22).

A stranger (gêr) is properly a guest residing in another country, whose rights are in a sense protected. He may be merely a temporary sojourner (tôshâb). But as a "stranger" (gêr) he has a recognized statusin the community. As a "sojourner" (tôshâb), he has none; he is a mere social "bird of passage." The difference is that between a "resident foreigner" and "a foreign visitor."

and shall serve them; and they shall afflict them The personal pronouns in English are ambiguous. There is a change of subject. Israel shall be slaves to the people of a land that is not theirs, i.e. to the Egyptians; and the Egyptians shall afflict them. The LXX δουλώσουσιν, "they, i.e. the Egyptians, shall make bondmen of them, i.e. the Israelites," gives a different turn to the first clause, and avoids the interchange of subject and object: cf. the quotation in Acts 7:6.

four hundred years See note on Genesis 15:16. The figure agrees in round numbers with the number of 430 years assigned, in Exodus 12:40, to the sojourning of Israel in Egypt. Cf. Acts 7:6; Galatians 3:17.