Ishmael and Isaac: children of one father.

It took me a few years writing this story about Hagar and her son Ishmael, and about Abraham, Ishmael’s father. And also about Sarah and her son Isaac, who is Ishmael’s half-brother. Ishmael and Isaac: they are children of one father.

It’s not difficult to find paintings on this subject. Many artists over the centuries have taken it up, drawn to the emotional and dramatic interaction between the figures. But I hesitated for a long time, because this story stands at a crossroads between Judaism, Christianity, and Islam. And over time, the story of Isaac and Ishmael as half-brothers – perhaps quarreling, as brothers do – has been used, or even abused, to explain political and religious tensions, especially in the long struggle between Arabs and Jews.

But that is not the story I want to tell. I want to approach it differently, as a story of shared origin. A story of children of one father.

Here are the topics we’ll explore, following the narrative of the Book of Genesis:

• Abraham, Sarah, Hagar, and Ishmael
• A son is promised to Sarah
• Two brothers: Ishmael and Isaac
• Abraham sends Hagar and Ishmael away
• Hagar and Ishmael in the desert
• Family reunion
• Bonus: from desert to pilgrimage – Hagar’s legacy in Mecca

Let’s start!

Abraham, Sarah, Hagar, and Ishmael

Let’s begin at the very beginning. With that odd old couple, Abraham and Sarah, both well over a hundred years old, and still no children! But Sarah has an idea!

They had grown old together, and the hope of ever having a child seemed to have faded. In the biblical account, it is Sarah who suggests that Abraham have a child with her young Egyptian maidservant, Hagar. Sarah blamed herself for their childlessness, saying, “The Lord has kept me from having children.” So she offered Hagar to Abraham, hoping to build a family through her. Abraham agreed, and Hagar became pregnant. She gave birth to a son, and they named him Ishmael. Abraham was the father.

A son is promised to Sarah

Then comes the next phase in the story. One day, Abraham and Sarah receive an unexpected visitor: an angel! The story makes it clear that this is a messenger of God, appearing in disguise.

The angel’s message sounds completely unbelievable: Sarah, at her advanced age, will have a son within a year. Abraham is told this directly. And he reacts with a gesture, as we see in Jan Provoost’s painting from the Louvre. Pointing toward his wife as if to say, “Her? At her age?” Sarah, standing in the doorway on the right, overhears it. Her reaction is the most human of all: she laughs. The Hebrew text says she laughs “within herself,” a kind of private chuckle of disbelief. One might say: she laughed out loud. The biblical version of LOL.

The name of the promised child will be Isaac, which fittingly means “he laughs.”

Two brothers: Ishmael and Isaac

Now there are two sons, Ishmael and Isaac. Two brothers, both children of Abraham, but from different mothers. Ishmael, the older, is the son of Hagar, Sarah’s Egyptian servant. Isaac, the younger, is the long-awaited child of Sarah, the mistress of the house.

Though they share a father, their positions could not be more different. One is born of a servant, the other of a free woman. One is firstborn, the other the child of promise.

The story suggests that there was tension between the boys. They were probably like any brothers, playing, teasing, perhaps quarreling? But Sarah becomes concerned. Or perhaps protective. She sees something, maybe rivalry, maybe mischief, and she is not pleased. In some versions, Ishmael is mocking Isaac. In others, it’s more ambiguous. But Sarah is firm. She turns to Abraham and tells him what she wants: send Hagar and Ishmael away.

In the print above, which I use to illustrate this scene, you can see Sarah speaking to Abraham in the foreground, and in the background, the two boys playing, fighting, hard to tell which. But the tension is there.

Abraham sends Hagar and Ishmael away

This next moment in the story has stirred the imagination of many artists. The emotional weight is immense: father and son, torn apart. Hagar, the mother, cast out. And Sarah, determined to protect her own child.

The Bible gives us the core of what happens. Sarah sees the two boys, Isaac and Ishmael, and she turns to Abraham and says, “Get rid of that slave woman and her son. He is not going to share the inheritance with my son, Isaac. I won’t have it.”

Abraham is deeply upset. Ishmael is his son. He does not want to send him away. But he listens, because a voice tells him to. For Abraham that’s the voice of God reassuring him that Isaac is the one through whom the family line will be counted. But God also gives Abraham this promise: “I will make a nation of the descendants of Hagar’s son because he is your son too.” That nation, in Islamic tradition, will be the Arab people. Ishmael is seen as the ancestor of the Arabs, and his role is honored as a founding figure.

So Abraham rises early the next morning. He prepares food, gives Hagar a supply of water, and sends her away with Ishmael. And the two of them wander into the desert.

This moment, the sending away, has become a favorite subject for painters and printmakers. And it is easy to see why. It is a perfect scene to show all the emotions: Abraham’s pain, Hagar’s grief, Ishmael’s innocence, Sarah’s determination. And the stillness of the moment before the wilderness swallows them.

Hagar and Ishmael in the desert

And so, Hagar and her son Ishmael find themselves alone in the desert. When the water runs out, Hagar breaks. In panic she runs up and down between the hills in the desert, all the time the same circle, and no water!

She places the boy in the shade and walks away, just far enough so she doesn’t have to watch him die. She sits down, weeping. Her words are raw: “I don’t want to watch the boy die.” It’s despair in its purest form. But then something shifts. The text in Genesis tells us that God hears the boy’s cries. An angel calls to Hagar — not one she sees, but one she hears: “Hagar, what’s wrong? Do not be afraid! Go to your boy and comfort him, for I will make a great nation from his descendants.”

In that moment, Hagar opens her eyes. And there, suddenly, is a well. Water. Life. She runs to fill her container and gives Ishmael a drink.

Ishmael survives. He grows up in the wilderness. He has many children, and through his line, the people of the Arab deserts trace their ancestry. This moment of despair, transformed by courage and grace, becomes the beginning of a nation.

This story isn’t just one of near-death and rescue — it’s also a story of inner voice, of resilience pushed into action. The Bible says Hagar heard the angel, not saw him. Perhaps the angel was not a visible figure, but a message rising up from within: “Please do not give up, but give it another try. There is still hope.” In Carel Fabritius’ painting, this is shown beautifully — the angel stands behind Hagar. She does not see him. She hears him, as an inner message of encouragement. And that makes all the difference. The image of Hagar in the desert, distraught and fearing for Ishmael’s life, is also an image of hope. This moment symbolizes the resilience and faith that inspire perseverance, even in the darkest times.

Family reunion

There is something deeply moving in how these family ties circle back. According to Arab tradition, Abraham — known as Ibrahim — and his son Ishmael reconciled later in life. Together, they built the Kaaba in Mecca, which became the spiritual heart of Islam. The well Hagar discovered, now called the Zamzam well, still flows near the Kaaba, inside the Great Mosque.

And in the Jewish and Christian traditions, Isaac and Ishmael too found each other again. When Abraham died at the age of 175, it was both his sons, Isaac and Ishmael, who came together to bury him. As it is written in Genesis: “Abraham lived for 175 years, and he died at a ripe old age, having lived a long and satisfying life. He breathed his last and joined his ancestors in death. His sons Isaac and Ishmael buried him in the cave of Machpelah.”

So perhaps this story, often seen as the origin of division, also carries the seeds of reunion. Two brothers, children of one father!

Bonus: from desert to pilgrimage – Hagar’s legacy in Mecca

To bring the story of Hagar and Ishmael into our present day, we can look to the sacred city of Mecca, where Muslims from around the world travel each year to perform the Hajj, the holy pilgrimage. This city of 2.5 million inhabitants, visited by more than 20 million pilgrims annually, was built on the site in the desert where Hagar found water for Ishmael, named as the Zamzam well.

Today, the Great Mosque of Mecca, the Masjid al-Haram, stands on this sacred ground. It is the most holy site in the Islamic world, and within its walls, several locations are directly tied to the story of Hagar, Ishmael, and Abraham (Ibrahim in the Islamic tradition):

• The Kaaba — the cuboid-shaped building at the heart of the mosque and the most sacred site in Islam. It is the structure that, according to tradition, was built or rebuilt by Abraham and Ishmael, together as father and son.
• The Hijr Ismail — a semicircular area adjacent to the Kaaba that pilgrims are not to walk upon. It marks the site where Abraham constructed a shelter for Hagar and Ishmael.
• The Zamzam Well — the water source discovered by Hagar after hearing the angel’s message to keep searching. To this day, pilgrims can receive a five-liter bottle of Zamzam water.
• Safa and Marwa — two small hills now enclosed within a covered passageway. This is where Hagar, in her desperation, ran back and forth seven times in search of water for her child. That journey is reenacted by pilgrims as part of the Hajj ritual.

So the footsteps of Hagar, a woman alone in the desert, a mother desperately searching for life for her son, are still being followed by millions today. Her strength, her voice, her perseverance have become a foundational memory in the faith of Islam.