וְנָתַתִּ֣י לְ֠ךָ וּלְזַרְעֲךָ֨ אַחֲרֶ֜יךָ אֵ֣ת ׀ אֶ֣רֶץ מְגֻרֶ֗יךָ אֵ֚ת כָּל־אֶ֣רֶץ כְּנַ֔עַן לַאֲחֻזַּ֖ת עוֹלָ֑ם וְהָיִ֥יתִי לָהֶ֖ם לֵאלֹהִֽים׃
Und ich werde dir und deinen Nachkommen nach dir das Land deines Aufenthaltes, das ganze Land Kanaan, zum ewigen Besitze geben, und ich will ihnen Gott sein.
Rashi on Genesis
לאחזת עולם FOR AN EVERLASTING POSSESSION — and there I will be your God; but whoever resides outside the land is as if he has no God (Ketubot 110b).
Radak on Genesis
ונתתי ... את ארץ מגורך, a reference to the locations in which Avraham had dwelled, not only these but the whole of the land of Canaan.
Sforno on Genesis
לאחוזת עולם, "I will be your G'd in order that you may carry out My will, and He gave them the land presently belonging to other nations in order that they keep His statutes." (Psalms 105, 44-45) When they do this they will achieve eternal existence individually, not merely as a species.