Or HaChaim on Genesis 12:8/אור החיים על בראשית י״ב:ח׳

1 ויעתק משם ההרה. He moved on from there to the hills. Seeing that the word ויעתק is transitive, the object seems to be missing in this verse. Rashi says that the object is Abraham's tent. This seems inadequate. Perhaps we have an allusion here that Abraham moved a rock [simile for G'd] from the place where G'd had appeared to him. This would correspond to something the sages said in Berachot 5 about the verse in Job 18,4: "Will earth's order be disrupted for your sake? Will a Rock be dislodged from His place?" The lesson here would be that whenever Israel moves from a place it has offered prayers to G'd, G'd moves with Israel. This concept was introduced by Abraham and Israel draws on Abraham's merit to this day in this respect.

2The message in this verse may also be that whenever Abraham put up his tent henceforth, he first dismantled the altar he had built and rebuilt it at the site he would erect his tent.