In the same day the LORD made a covenant with Abram, saying,
Unto your descendants have I given this land, from the river of Egypt unto the great river, the river Euphrates:
All Commentaries on Genesis 15:18 Go To Genesis 15
Ambrose of Milan
AD 397
Foreign peoples are given to Abraham as though for education and so that the most scrupulous mind of the just person might cut away their vices and correct their errors. But what is most evident here is rather the mystery of the church. Through its apostles, “who are Israelites, to whom belong the patriarchs,” and from whose patriarchs “Christ was born according to the flesh” under the law, the church was to be constituted from the gathering of pagan peoples who would believe. And it is not by accident that these are indicated by the number ten but rather to show that these, at first unbelievers, when they had completed the measure of impiety, would certainly obtain the crown of faith. .