And Sarah my master's wife bore a son to my master when she was old; and to him he has given all that he has.
So she said to Abraham, “Cast out this slave woman with her son; for the son of this slave woman shall not be heir with my son Isaac.”
Abraham gave all he had to Isaac.
He did not weaken in faith when he considered his own body, which was as good as dead because he was about a hundred years old, or when he considered the barrenness of Sarah's womb.