Genesis 21:2-12

2 Sarah conceived and bore Avraham a son in his old age, at the very time God had said to him.
3 Avraham called his son, born to him, whom Sarah bore to him, Yitz'chak.
4 Avraham circumcised his son Yitz'chak when he was eight days old, as God had ordered him to do.
5 Avraham was one hundred years old when his son Yitz'chak [laughter] was born to him.
6 Sarah said, "God has given me good reason to laugh; now everyone who hears about it will laugh with me."
7 And she said, "Who would have said to Avraham that Sarah would nurse children? Nevertheless, I have borne him a son in his old age!"
8 The child grew and was weaned, and Avraham gave a great banquet on the day that Yitz'chak was weaned.
9 But Sarah saw the son of Hagar the Egyptian, whom Hagar had borne to Avraham, making fun of Yitz'chak;
10 so Sarah said to Avraham, "Throw this slave-girl out! And her son! I will not have this slave-girl's son as your heir along with my son Yitz'chak!"
11 Avraham became very distressed over this matter of his son.
12 But God said to Avraham, "Don't be distressed because of the boy and your slave-girl. Listen to everything Sarah says to you, because it is your descendants through Yitz'chak who will be counted.
Complete Jewish Bible Copyright 1998 by David H. Stern. Published by Jewish New Testament Publications, Inc. All rights reserved. Used by permission.