Genesis 21

God visits Sarah and she concieves.

21:1 And the LORD visited Sarah as he had said, and the LORD did unto Sarah as he had spoken.

21:2 For Sarah conceived, and bare Abraham a son in his old age, at the set time of which God had spoken to him.

21:3 And Abraham called the name of his son that was born unto him, whom Sarah bare to him, Isaac.

21:4 And Abraham circumcised his son Isaac being eight days old, as God had commanded him.

21:5 And Abraham was an hundred years old, when his son Isaac was born unto him.

21:6 And Sarah said, God hath made me to laugh, so that all that hear will laugh with me.

21:7 And she said, Who would have said unto Abraham, that Sarah should have given children suck? for I have born him a son in his old age.

(21:1-7) The LORD visited Sarah as he had said, and the LORD did unto Sarah as he had spoken.

(21:2) And "Sarah conceived and bare Abraham a son." (God-assisted conceptions never result in daughters.)

It is strange that the 100 year old Abraham required God's help in fathering Isaac (See Rom.4:19 and Heb.11:12), yet later (Gen.25:1-2) he marries again and has six more children without any help from God.
How many sons did Abraham have?
How many generations from Abraham to Moses?
Barren women in the Bible

Sarah tells Abraham to abandon his first son, Ishmael.
(Because she saw him "mocking" Isaac.)

21:8 And the child grew, and was weaned: and Abraham made a great feast the same day that Isaac was weaned.

21:9 Sarah saw the son of Hagar the Egyptian, which she had born unto Abraham, mocking.

21:10 Wherefore she said unto Abraham, Cast out this bondwoman and her son: for the son of this bondwoman shall not be heir with my son, even with Isaac.

21:11 And the thing was very grievous in Abraham's sight because of his son.

(21:8-10) Sarah saw the son of Hagar ... mocking. Wherefore she said unto Abraham, Cast out this bondwoman and her son.

Abraham had a feast to celebrate the day that Isaac was weaned. On that same day, apparently, Sarah saw Ishmael "mocking" his newly-weaned little brother. So, once again (see Gen 16:5-6), Sarah tells Abraham to "cast out this bondwoman and her son."

What did Sarah see that disturbed her so much?
Jonathan Kirsch suggests in The Harlot by the Side of the Road that the "play" between Isaac and Ishmael may have been of a sexual nature, noting that the same word is used to describe the behavior of Ishmael and Isaac as is used in Gen 26:8 to describe Isaac's fondling of Rebekah.
Strange Flesh: Ishmael and Isaac - What did Sarah see?

God tells Abraham to do as Sarah says.
(Abandon Ishmael and his mother, Hagar.)

21:12 And God said unto Abraham, Let it not be grievous in thy sight because of the lad, and because of thy bondwoman; in all that Sarah hath said unto thee, hearken unto her voice; for in Isaac shall thy seed be called.

21:13 And also of the son of the bondwoman will I make a nation, because he is thy seed.

(21:12-14) God said unto Abraham ... hearken unto her voice.

God commands Abraham to "hearken unto her voice." So Abraham abandons Hagar and Ishmael, casting them out into the wilderness to die.
What the Bible says about fathers

Abraham does as he's told.
(An angel rescues them before they die of thirst.)

21:14 And Abraham rose up early in the morning, and took bread, and a bottle of water, and gave it unto Hagar, putting it on her shoulder, and the child and sent her away: and she departed, and wandered in the wilderness of Beersheba.

21:15 And the water was spent in the bottle, and she cast the child under one of the shrubs.

21:16 And she went, and sat her down over against him a good way off, as it were a bow shot: for she said, Let me not see the death of the child. And she sat over against him, and lift up her voice, and wept.

21:17 And God heard the voice of the lad; and the angel of God called to Hagar out of heaven, and said unto her, What aileth thee, Hagar? fear not; for God hath heard the voice of the lad where he is.

21:18 Arise, lift up the lad, and hold him in thine hand; for I will make him a great nation.

21:19 And God opened her eyes, and she saw a well of water; and she went, and filled the bottle with water, and gave the lad drink.

21:20 And God was with the lad; and he grew, and dwelt in the wilderness, and became an archer.

21:21 And he dwelt in the wilderness of Paran: and his mother took him a wife out of the land of Egypt.

(21:14-20) After the water ran out, Hagar left Ishmael alone to die.

But God heard the infant crying, so he had an angel cry to Hagar from heaven, telling her not to worry.

God opened Hagar's eyes so she could see a well, filled with water.

He said he'd make Ishmael a great nation, and the child became an archer.

(21:15,18) In these verses, Hagar "casts the child under one of the shrubs" and later holds him in her hand, implying that Ishmael was an infant when he was abandoned by Abraham.
How old was Ishmael when he was abandoned?

Abraham swears to God.


21:22 And it came to pass at that time, that Abimelech and Phichol the chief captain of his host spake unto Abraham, saying, God is with thee in all that thou doest:

21:23 Now therefore swear unto me here by God that thou wilt not deal falsely with me, nor with my son, nor with my son's son: but according to the kindness that I have done unto thee, thou shalt do unto me, and to the land wherein thou hast sojourned.

21:24 And Abraham said, I will swear.

21:25 And Abraham reproved Abimelech because of a well of water, which Abimelech's servants had violently taken away.

21:26 And Abimelech said, I wot not who hath done this thing; neither didst thou tell me, neither yet heard I of it, but to day.

21:27 And Abraham took sheep and oxen, and gave them unto Abimelech; and both of them made a covenant.

21:28 And Abraham set seven ewe lambs of the flock by themselves.

21:29 And Abimelech said unto Abraham, What mean these seven ewe lambs which thou hast set by themselves?

21:30 And he said, For these seven ewe lambs shalt thou take of my hand, that they may be a witness unto me, that I have digged this well.

(21:21-24) Abimelech asked Abraham to swear to God that he'll be nice to him, his son, and grandson. And Abraham does so.
Is it OK to swear?

21:31 Wherefore he called that place Beersheba; because there they sware both of them.

(21:31) Wherefore he called that place Beersheba.
Who named Beersheba?

21:32 Thus they made a covenant at Beersheba: then Abimelech rose up, and Phichol the chief captain of his host, and they returned into the land of the Philistines.

21:33 And Abraham planted a grove in Beersheba, and called there on the name of the LORD, the everlasting God.

21:34 And Abraham sojourned in the Philistines' land many days.

(21:32) They returned to the land of the Philistines.
But the Philistines didn't arrive in the region of Canaan until around 1200 BCE -- 800 years after Abraham's supposed migration from Ur.