When the time comes for Avraham to separate from Lot, Avraham poses the following deal to Lot: 'the entire land is in front of you - if you go left I'll go right, and if you go right I'll go left' (13:9).
The Netziv asks an interesting question here. Why does Avraham need to move here; let Lot go left/right and Avraham should stay where he is? Why do they both need to move in opposite directions in order to be apart?
The Netziv answers that Avraham wanted to
show that he cared for Lot and his feelings.
In order that Lot should not feel troubled and bothered for having to move, Avraham said that he would also undergo the ordeal of moving all his possessions away. Just like you, Lot, move one way, I, Avraham will move the other way - that way we'll both have the same exertion. is the way of a tzaddik; he cares for even the smallest of things when it comes to others' feelings.