Why Hagar Came to Sarai and Eliezer to Abraham

"And Sarai, Abram's wife, had not borne him [a child]" (Genesis 16:1). The Sages, of blessed memory, said: she had no offspring — that is to say, no womb (literally, "house of offspring"). "And she had a maidservant, an Egyptian, and her name was Hagar" (Genesis 16:1). Pharaoh gave his daughter to Sarai as a maidservant at the time that he took her. And therefore she was called Hagar, for thus he said to Sarai: "Here is your reward" (Hā agrēkh). And likewise Nimrod gave Eliezer his son to Abraham at the time that he was saved from the fiery furnace.