I dunno, I never really read the chapter...God was probably planning on making Abraham's tribe his chosen people anyway, considering the alternatives. It was Abraham or some Baal worshippers, so God went with the fundamentalist lunatic instead of the demon-worshipping pagans.
And that's why Jerry Falwell is a Christian and the people who wear funny clothes and talk about Earth Crystals and Goddess Energy are not. </kidding, again>
'nuff said