John Calvin on Genesis 13:9

9. Is not the whole land before thee ? Here is that moderation of which I have spoken; namely, that Abram for the sake of appeasing strifes voluntarily sacrifices his own right. For as ambition and the desire of victory Φιλονεικία is the mother of all contentions; so when every one meekly and moderately departs, in some degree, from his just claim, the best remedy is found for the removal of all cause of bitterness. Abram might indeed, with an honorable pretext, have more pertinaciously defended the right which he relinquished, but he shrinks from nothing for the sake of restoring peace: and therefore he leaves the option to his nephew.