כִּ֧י אֶל־אַרְצִ֛י וְאֶל־מוֹלַדְתִּ֖י תֵּלֵ֑ךְ וְלָקַחְתָּ֥ אִשָּׁ֖ה לִבְנִ֥י לְיִצְחָֽק׃
But thou shalt go unto my country, and to my kindred, and take a wife for my son, even for Isaac.’
Rashbam on Genesis
כי אם אל ארצי, not to members of any nation which does not dwell physically close to the region from which I originate. This is where you shall go to conduct your search.
Or HaChaim on Genesis
כי אל ארצי ואל מולדתי תלך, "rather you shall go to my country and to my birthplace, etc." This was part of the oath also; Eliezer was to secure a wife for Isaac in Abraham's birthplace. This is why Eliezer is described as immediately taking the camels, etc.