Ishmael and Isaac bury their father Abraham
From the 1728 Figures de la Bible; illustrated by Gerard Hoet (1648-1733)
Alice C. Linsley
Ishmael (Yishmael) is recognized as one of Abraham's sons in Christianity, Islam, and Judaism. He was born to Hagar (Hājar), an Egyptian concubine (Gen. 16:3). According to the marriage and ascendancy pattern of Abraham the Hebrew, this meant that Ishmael was not Abraham's proper heir. The proper heir would be Isaac, the first-born son of Abraham's first wife (and half-sister) Sarah.
It appears that the first-born sons of wives ruled territories while the first-born sons of concubines ruled settlements in obedience to their ruling brothers. This is similar to the "nomes" of Egypt, where each was ruled by a tribal chieftain whose allegiance was to the higher ranking ruler.