Genesis 24:3

“And I will make thee swear by the Lord, the God of heaven, and the God of earth, etc.] The Maker and possessor of heaven and earth, by whom Abraham used to swear whenever he did, and by whom only men should swear, (see <011422>Genesis 14:22). The Targum of Jonathan is, “I will make thee swear by the name of the Word of the Lord God,” which strengthens the sense given of the rite before observed: that thou wilt not take a wife unto my son of the daughters of the Canaanites, among whom I dwell; these being not only idolaters, and very wicked people, degenerated yet more and more, but were the seed of the accursed Canaan; and who in process of time would be dispossessed of the land, and be…”

“thou shalt not take a wife, &c.--Among pastoral tribes the matrimonial arrangements are made by the parents, and a youth must marry, not among strangers, but in his own tribe--custom giving him a claim, which is seldom or never resisted, to the hand of his first cousin. But Abraham had a far higher motive--a fear lest, if his son married into a Canaanitish family, he might be gradually led away from the true God.”

“24:3 Isaac knew how wicked and threatening the local Canaanite people were, so he maintained separation from them (cp. 26:34-35; 27:46; 28:8-9).”