In The Kingdom, what was with the scene...

Well, there was this gal, name of Hagar, who was instructed by a gal, name of Sarah, whose plumbing apparently didn't work quite right, to bear a son for Sarah's husband, name of Abraham. And this son, named Ishmael, was sent out into the lifeless desert, along with his Momma Hagar, by Sarah, presumeably because the situation had suddenly become way too complicated. But they were saved, by Jehovah, as it turns out, and lived to found a people, known by some as the Ishmaelites, and by others as the Arabs.

The scene is not pointless, just the argument. God, whether you call him Jehovah or Allah, loves both wives equally, and wishes both of them an equal chance at survival and prosperity. The point of the scene is, men whose wives have just been blown to bits generally don't recall these finer points of their religious literatures. Then again, men who kill other men's wives by blowing them to bits generally don't recall them either. The moral of the story: Don't go around killing wives, by blowing them up, or sending them into the desert. No matter how complicated the situation, you're only likely to make it worse.