Genesis
Chapter 21
The Birth of Isaac
The Lord was kind to Sarah as he had said and fulfilled his promise to her.
Sarah became pregnant and bore a son to Abraham in his old age, at the very time the Lord had promised.
Abraham named the son that Sarah bore him Isaac
and circumcised him when he was eight days old, as the Lord had commanded.
Abraham was a hundred years old when his son Isaac was born to him.
Sarah said:
“God has brought me laughter, and everyone who hears of this will laugh with me.”
She added:
“Who would have told Abraham that Sarah would nurse children? Yet I have given birth to a son for him in his old age.”
The child grew, and Abraham held a great feast on the day Isaac was weaned.
Sarah saw the child whom Hagar, the Egyptian, had borne to Abraham, mocking her son
and she said to Abraham:
“Send this slave girl and her son away; the child of this slave must not share the inheritance with my son, Isaac.”
This matter troubled Abraham because it involved his son.
But God said to him:
“Don’t be worried about the boy and your maidservant. Listen to Sarah and do whatever she says, because the race, which is called by your name, will spring from Isaac.
But from the son of your servant I will also form a nation, for he too is your offspring.”
Abraham woke up early the next morning and gave Hagar bread and a skin of water. He placed the child on her back and sent her away. She went off and wandered in the desert of Beer-sheba.
When there was no more water in the skin, she pushed the boy under one of the bushes,
and then sat down about a hundred yards away, for she thought, “I cannot bear to see my son die.” But as she sat there, the child began to wail.
God heard him, and the angel of God called to Hagar from heaven and said:
“What is the matter, Hagar? Don’t be afraid. God has heard the boy crying.
Get up, pick the boy up, and hold him safely, for I will make him into a great nation.”
God then opened her eyes, and she saw a well of water. She went and filled the skin and gave the boy a drink.
God was with the boy as he grew up, made his home in the wilderness, and became an expert archer.
He lived in the desert of Paran, and his mother selected a wife for him from Egypt.
Abraham and Abimelech
At that time, Abimelech came with Phicol, the commander of his army, to speak to Abraham:
“God is with you in everything you do;
swear to me here before God that you will not deal falsely with me or my descendants, but instead you will show me and the country where you are living the same kindness that I have shown you.”
And Abraham said:
“Yes, this I swear.”
Then Abraham complained to Abimelech about a well that Abimelech’s servants had seized.
Abimelech said:
“I don’t know who has done this; you did not tell me, and I only heard about it today.”
Abraham then took sheep and cattle and gave them to Abimelech, and the two men made a treaty.
Abraham set aside seven ewe lambs from the flock.
Abimelech said to him:
“Why have you put aside these seven ewe lambs?”
Abraham replied:
“Accept these seven lambs from my hand as evidence that I dug this well.”
The place was called Beersheba because the two men took an oath there.
After making the treaty at Beersheba, Abimelech went away with Phicol, the commander of his army, and returned to the land of the Philistines.
Abraham planted a tamarisk tree at Beersheba and there he called on the Lord, the everlasting God.
And Abraham stayed in the land of the Philistines for a long time.

Commentaries
The Birth of Isaac.
This text consists of two distinct parts. The first (1-8) discusses the fulfillment of the promise (17:15f) regarding the birth of Isaac and features the words of Sarah (6f), the earliest recorded words in the entire history of the matriarchs. The redactors recount the tradition that it is the father’s role to name the children (3), the law mandating circumcision on the eighth day (4), and the custom of holding a feast on the day of the infant’s weaning (8). However, the key message is found in the second part (9-21), where the fates of Ishmael and Isaac are established. Ishmael will also share in the blessing and the promise of many descendants that will carry on after Abraham through Isaac (13b.18).
This story should not be seen as a narration of the fate of Isaac—the Hebrew people—and Ishmael—the Ishmaelites or Arabs. Instead, it confirms the relationship between the two ethnic groups, whose origins are lost in time. The story serves as a literary resource to establish the moment when the enduring antagonism between these two groups begins.
Abraham and Abimelech.
As Abraham is the great patriarch of the South, the redactor or redactors of the Pentateuch must establish the location or locations where he settles. It is essential to recall that one of the purposes of reinterpreting the stories of the patriarchs is to connect them to the period of the united monarchy and to establish the figure of the king in continuity with the ancestors of Israel and the places of their wanderings.