6 links
Abraham and the Child of Sacrifice: Isaac or Ishmael?
answering-islam.org
Deconstruction of the extra-Koranic Muslim tradition that Ishmael, not his brother, was the intended sacrifice of Genesis.
Catholic Encyclopedia: Ismael
newadvent.org
Commentary on the spurned son of Abraham from the traditional Catholic perspective.
Comparative Index to Islam: Ishmael
answering-islam.org
Highlights differences between Islamic and Christian beliefs about the illegitimate son of Abraham.
Jewish Virtual Library: Ishmael
jewishvirtuallibrary.org
Brief profile of the illegitimate son of Abraham, with links to pertinent Torah passages.