You're exactly right. But Ishmael was not the child of the promise. That was Isaac.
The LORD told Abraham and Sarah that they will have a child. Only Isaac fulfilled that promise because he was sired in the union of Abraham and Sarah.
Abraham sired Ishmael but that was only of the flesh.
"Abraham sired Ishmael but that was only of the flesh. "
Which is usually good for the throne of England, if I'm not mistaken...
Of course, English monarchy rules of ascencion obviously weren't in place the time of Abraham! Thanks for the reply!
Does make a difference, one supposes, to have been prophesied!