Genesis 24:3

And I will make thee swear by the Lord, the God of heaven, and
the God of earth
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 ( 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 destroyed. Now though Isaac was forty years of age, and one would think at an age sufficient to have chosen a wife for himself; but as Abraham knew that he had a great respect for this servant, and would be influenced by him in such a choice, and especially as this affair was now about to be committed to his care, and no doubt with the consent of Isaac, therefore he thus charges and adjures him.