Or HaChaim on Genesis 26:2/אור החיים על בראשית כ״ו:ב׳

1 שכון בארץ אשר אמר אליך. "Dwell in the land I shall tell you to." This was a general directive to accept G'd's instructions where he was to take up residence even if it conflicted with his own wishes. G'd told him this in order to be able to reward him for obeying. G'd had done something similar when He told Abraham in 12,1 that he was to go to a place G'd would designate (in the future). Five verses later on G'd specified the land, i.e. "the land of Canaan," something He could have done immediately were it not for the fact that He wanted Abraham to accumulate merit for obeying His directive.