Sarah (she was called “Sarai” back then) was the first of a long line of barren women who were desperate for children.1 (In the Bible, it is always the women who are barren, never the men.) So she sent Abraham (“Abram”) “in unto” her slave, Hagar, so that she could "obtain children by her." Abraham did as he was told and impregnated Hagar.
Now Sarai Abram's wife bare him no children: and she had an handmaid, an Egyptian, whose name was Hagar. And Sarai said unto Abram, Behold now, the LORD hath restrained me from bearing: I pray thee, go in unto my maid; it may be that I may obtain children by her. And Abram hearkened to the voice of Sarai. Sarai ... took Hagar her maid the Egyptian ... and gave her to her husband Abram to be his wife. And he went in unto Hagar, and she conceived. Genesis 16:1-4Soon Sarah became jealous of Hagar, treating her so badly that Hagar ran away. Then an angel appeared and told Hagar to return to her abusive mistress. So she did, and amid this messed up family life situation, Ishmael was born.
When Sarai dealt hardly with her, she fled from her face. And the angel of the LORD found her ... And he said ... Return to thy mistress, and submit thyself under her hands ... Behold, thou art with child and shalt bear a son, and shalt call his name Ishmael. 16:6-11Fourteen years later, God helped Sarah get pregnant, and Isaac was born.2 Then one day, after Isaac was weaned, Sarah saw the teenage Ishmael “mocking” his two-year-old brother.
The child [Isaac] grew, and was weaned ... And Sarah saw the son of Hagar the Egyptian, which she had born unto Abraham, mocking. Genesis 21:8-9The Bible doesn’t say what Ishmael did to “mock” his little brother Isaac. But whatever it was it upset Sarah so much that she told Abraham to abandon Ishmael and his mother Hagar.
Wherefore she said unto Abraham, Cast out this bondwoman and her son. Genesis 21:10Some have suggested that Ishmael’s “mocking” of his younger brother Isaac was of a sexual nature, noting that the same word (tzahak) is used to describe the behaviour in this verse is used in Genesis 26:8 to describe Isaac's fondling of his wife Rebekah.3
Abimelech king of the Philistines looked out at a window, and saw, and, behold, Isaac was sporting with Rebekah his wife. Genesis 26:8If so, that might explain Sarah’s hostility toward Ishmael. But whatever it was, God agreed with Sarah, telling Abraham to abandon Hagar and Ishmael.
And God said unto Abraham ... hearken unto her voice. Genesis 21:12Maybe God saw what Sarah saw.
'The Expulsion of Hagar', Adrien van der Werfft
- Barren women in the Bible: Sarah (Genesis 16:1); Rebekah (Genesis 25:21); Leah (Gen 29:31); Rachel (Genesis 30:1); Manoah’s wife, Samson’s mother (Judges 13:2); Hannah, Samuel’s mother (1 Samuel 1:5); Elizabeth, John the Baptist’s mother (Luke 1:7).
- Abraham was 86 years old when Ishmael was born.
And Abram was fourscore and six years old, when Hagar bare Ishmael to Abram. Genesis 16:1And he was 100 years old when Isaac was born.
The Lord visited Sarah ... and ... did unto Sarah as he had spoken. For Sarah conceived, and bare Abraham a son in his old age. And Abraham called the name of his son that was born unto him, whom Sarah bare to him, Isaac…. And Abraham was an hundred years old, when his son Isaac was born unto him. Genesis 21:1-5So, according to the Genesis story, Ishmael was 14 years older than Isaac.
- The Hebrew verb tzahak … can mean ‘to laugh with’ as well as ‘to fondle sexually,’ as it does in the story about Rebecca and Isaac fondling each other in Gerar (Gen. 26:8)” Gerald Larue, Sex and the Bible, p. 99; See also Jonathan Kirsch, Moses, p. 48-51.