It was God's plan that through Abraham and his descendants the whole world should learn of the "good news" of salvation from sin and death, through Christ who was to suffer for men, and thus buy them back to God and happiness.
But Abraham had no children, and Sarah, his wife, did not believe that God would give her a son. So she got Abraham to marry her Egyptian maid, Hagar. But the Lord said that His promise was not to be fulfilled through Ishmael, the son of this woman, but through a son whom He would give Sarah. So after Isaac was born, Hagar and Ishmael were sent away; for the Lord had said, "In Isaac shall thy seed be called."
The Flight from Sodom.
