Now therefore swear unto me here by God
By the true and living God, by whom only an oath is to be taken, who was Abraham's God, and whom Abimelech seems to have known and to have been a worshipper of; and therefore moves for an oath to be taken by him, which he knew would be sacred and binding to Abraham, could he prevail upon him to swear:
that thou wilt not deal falsely with me, nor with my son, nor with my
son's son;
perhaps he had heard that God had promised to give the whole land of Canaan to him and his posterity, and among the rest his kingdom, which was a part of it; and, seeing him grow great and powerful, he could not tell how soon it might be ere he was put in the possession of it, whether in his own time, or his son's, or his grandson's; and therefore desires Abraham that he would swear to do no hurt to them whenever it should be;
[but] according to the kindness I have done unto thee, thou shalt do
unto me, and to the land wherein thou hast sojourned;
that, as he had given him full liberty to sojourn in any part of his kingdom where he pleased, so, when the whole country should come into his possession, that he, or his son, or his grandson, in whatsoever time it should be, might quietly enjoy their own land, and all the inhabitants of it; at least that they might not be driven out of it, but sojourn in it as he had done.
The Brenton translation of the Septuagint is in the public domain.