"400 Years" verse 13
"boundaries... marked out in the Covenant" verse 18
"reconfirmed specifically to Abraham" verse 18
15:13 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;
15:14 And also that nation, whom they shall serve, will I judge: and afterward shall they come out with great substance..............
15:18 In the same day the Lord made a covenant with Abram, saying, Unto thy seed have I given this land, from the river of Egypt unto the great river, the river Euphrates: