Genesis 24:3

the God of heaven … earth This solemn title of Jehovah as God of the whole universe is more common in later Hebrew writings; cf. Ezra 5:11. This form of adjuration indicates the conviction of the writer that the God of the Hebrews was the God of the whole world, not merely of a particular locality or nation: compare Genesis 18:25. No change of country, no lapse of time, would constitute an exemption from the binding character of the oath.

of the daughters of the Canaanites The dread of the marriage of an Israelite with a Canaanite which is found here, is also expressed in Genesis 26:34-35; Genesis 27:46; Exodus 34:16; Deuteronomy 7:3; Ezra 9:2. For "Canaanite," cf. Genesis 10:18-19; Genesis 12:6; Genesis 13:7 (J).

Religious feeling underlies this prohibition. The purity of the Hebrew race is to be maintained. Intermarriage would involve participation in religious rites. Separateness would give a corresponding freedom from moral contamination.