Hagar: Sarah had no son, so Abraham, wanting to continue his line, took Hagar for his second wife. Hagar bore him a son, Ishmael, whereupon Sarah conceived and likewise had a son, named Isaac. Sarah then demanded that Abraham banish Ishmael and Hagar from the tribe.
Ishmael & Isaac: Of Abraham’s two sons, Ishmael and Isaac, Muslims claim descent through the former, Jews through the latter. Isaac’s son, Jacob, is a pivotal figure, for it is his twelve sons who become the patriarchs of the twelve tribes of Israel.