The LORD appeared again to Abraham while he was camped near the oak grove belonging to Mamre. One day about noon, as Abraham was sitting at the entrance to his tent,
he suddenly noticed three men standing nearby. He got up and ran to meet them, welcoming them by bowing low to the ground.
"My lord," he said, "if it pleases you, stop here for a while.
Rest in the shade of this tree while my servants get some water to wash your feet.
Let me prepare some food to refresh you. Please stay awhile before continuing on your journey." "All right," they said. "Do as you have said."
So Abraham ran back to the tent and said to Sarah, "Quick! Get three measures of your best flour, and bake some bread."
References for Genesis 18:6
Then Abraham ran out to the herd and chose a fat calf and told a servant to hurry and butcher it.
When the food was ready, he took some cheese curds and milk and the roasted meat, and he served it to the men. As they ate, Abraham waited on them there beneath the trees.
"Where is Sarah, your wife?" they asked him. "In the tent," Abraham replied.
Then one of them said, "About this time next year I will return, and your wife Sarah will have a son." Now Sarah was listening to this conversation from the tent nearby.
And since Abraham and Sarah were both very old, and Sarah was long past the age of having children,
she laughed silently to herself. "How could a worn-out woman like me have a baby?" she thought. "And when my master -- my husband -- is also so old?"
Then the LORD said to Abraham, "Why did Sarah laugh? Why did she say, 'Can an old woman like me have a baby?'
Is anything too hard for the LORD? About a year from now, just as I told you, I will return, and Sarah will have a son."
Sarah was afraid, so she denied that she had laughed. But he said, "That is not true. You did laugh."