Abraham had many sons, (See Genesis 25:1-6), but none of these sons were chosen by God.....not even Ishmael who was Abraham's first born. It was through Isaac's line that the Davidic Kingdom was to come. God made a covenant with Abraham and promised him that he would have many descendants. God kept His promise, but only ONE of Abraham's descendants became the chosen people of God. God did not make ALL of Abraham's descendants His chosen people.
Issac then had two sons, but God's chosen one was Jacob, who was a liar and a cheater. God did not choose Essau. So, although Essau was a Hebrew and son of Issac and a descendant of Abraham, Essau's descendants were not God's chosen people.
Jacob then had 12 sons. Of the 12, it was Joseph who was sold by his brothers into Egypt. Later, Joseph allowed his father Jacob and 11 other brothers to stay in Egypt. It was the descendants of Jacob that became God's chosen people.....and these descendants were slaves in Egypt.