Kedma was the youngest of Ishmael's twelve sons and thus a grandson of Abraham. He became the ancestor of an Arab tribe, and his name is mentioned in the genealogies in Genesis and 1 Chronicles. As one of Ishmael's twelve sons, he fulfilled God's promise that Ishmael would become the father of twelve princes.
God promised Abraham that Ishmael would be fruitful and become the father of twelve princes, which was fulfilled through Kedmah and his eleven brothers.
20As for Ishmael, I have heard you. I will surely bless him; I will make him fruitful and multiply him greatly. He will father twelve princes, and I will make him into a great nation.
18His descendants settled from Havilah as far as Shur, near the border of Egypt, in the direction of Asshur; and they lived in hostility toward all their kindred.