So God incited Abraham to abandon his older son, Ishmael?
I don't think Abraham ever abandoned Ishmael. Much to Keith's disappointment the Bible is not the only source of information. There are references to Abraham spending lots of time with Hager and Ishmael during Ishmael's lifetime including when Ishmael was grown and married. Religious peoples like to talk about miracles they read about in old books. Now while the origin of the zam zam well is written in old books and is open to discussion, if one was to acknowledge that it began as a water source for baby Ishmael, then that miracle is still available and can be seen with the physical eyes some 9000 years later.