Genèse 24:3

And swear to me in the name of the Word of the Lord God, whose habitation is in heaven on high, the God whose dominion is over the earth, that thou wilt not take a wife for my son from the daughters of the Kenaanites among whom I dwell;

1. And the reason for telling us the God of the Heavens and the God of the land is because in this place when a daughter is set up with someone (a shidduch) it is really from Heaven. And this is a secret.

AND I WILL MAKE THEE SWEAR BY THE ETERNAL. It would have been proper for Abraham to command his son Isaac that he should not take a wife from the daughters of Canaan. But since it was his wish to dispatch someone during his lifetime to his country and his family, and he made the servant swear to do so whether in his lifetime or after his death, therefore Abraham found it necessary in any case to make the servant swear to go there. In addition he found it necessary to say to him, “I command you that you should not take a woman for my son of the daughters of Canaan. Instead you are to go to my country and take for him a wife from my father’s house.” Now having required the servant to swear to this, he no longer found it necessary to command Isaac at all for he knew that he would not transgress his father’s wish or the oath which he made his servant swear, as the matter was indeed known to Isaac.
It is also possible that the servant Eliezer was the administrator of his possessions, and Abraham commanded him to marry off Isaac in accordance with his will and cause him to inherit his estate on this condition, [namely, that he marry in accordance with his father’s wish]. This is the significance of the expression, that ruled over all that he had.

THE G-D OF THE HEAVEN, AND THE G-D OF THE LAND. (the land) to mean “the land of Israel.” The Holy One, blessed be He, is called the G-d of the Land of Israel, as it is written, They know not the manner of the G-d of the land, and it is further written, And they spoke of the G-d of Jerusalem, as of the gods of the people of the earth. There is a secret in this matter which I will yet explain with the help of G-d. However [in Verse 7], further on where it says, Who took me from my father’s house, it does not say “the G-d of the land” because he [Abraham] was then in Haran or Ur of the Chaldees. So also the Rabbis have said: “He who lives outside the land of Israel is as if he had no G-d, as it said, For they have driven me out this day that I should not cleave unto the inheritance of the Eternal, saying, Go, serve other gods. However this verse teaches you that he who lives outside of the land of Israel is considered as if he worshipped idols. (Ibid.)

אלוקי השמים ואלוקי הארץ, a veiled warning to Eliezer that if he were to betray his trust, there would be a higher power to hold him accountable for such a betrayal.

ואשביעך..ואלוקי הארץ, meaning that the same G’d Who is ruler in the heavens also exercises His control down here on earth. Do not think that if you do not honour an oath made to the G’d in heaven that failure to honour it would not have negative consequences for you here on earth. When Avraham speaks of his own self, as opposed to the need to make someone else take an oath, he only needs to refer to the “G’d of the heavens” (compare verse 7) Avraham was well aware of G’d being also the G’d on earth. In Bereshit Rabbah 59,8 Rabbi Pinchas is quoted as saying that until He revealed Himself to His creatures G’d was known only as the “G’d of the heavens,” whereas after He revealed Himself to His creatures [or to an individual creature by performing a miracle for such a person Ed.] He also became known as the ”G’d of the earth.”

מבנות הכנעני, for the entire Canaanite tribe is cursed since the days of Noach, and Avraham’s seed is not to be merged with that of a cursed tribe.

יושב בקרבו, compare the verses 36 in our chapter as well as Genesis 48,16 where one or the other of these words is used to describe the environment in which our patriarchs lived.