God had already promised Abraham that he would become the father of a great nation, but there was an obvious problem. Abraham and Sarah still had no children together, Abraham was nearly 100 years old, and Sarah was about 90. When God told Abraham that Sarah would have a son, Abraham laughed. Genesis 17 says he “fell on his face and laughed” and wondered whether a child could really be born to a 100-year-old man and a 90-year-old woman. God answered him plainly. He said that Sarah would have a son, they would name him Isaac, and that He would establish His covenant with him.
Not long afterward, three visitors came to Abraham near the oaks of Mamre. Abraham welcomed them, fed them, and stood nearby while they ate. Sarah was inside the tent when one of the visitors said that he would return at that time the following year and Sarah would have a son. Sarah laughed to herself and wondered how this could possibly happen when she and Abraham were both so old.
The LORD heard her laugh and had a couple of questions for Abraham.
“Why did Sarah laugh and say, ‘Shall I actually give birth to a child, when I am so old?’”
“Is anything too difficult for the LORD?”
Sarah wasn’t wrong about the biology. Having a baby at her age was impossible by any normal human measure. God wasn’t asking her to pretend that being 90 years old and pregnant was perfectly ordinary. He was asking her to consider whether the limits that applied to Sarah also applied to Him.
Nothing is too difficult for God.
Sarah apparently realized that the LORD had heard the laugh she thought she’d kept to herself, because she became afraid and denied it. “I did not laugh.” His response was wonderfully direct – “No, but you did laugh.”
The laughter didn’t end there. Abraham had laughed. Sarah had laughed. Then the impossible thing actually happened. Sarah became pregnant and gave birth to a son at exactly the time God had promised.
They named him Isaac, just as God had instructed. His Hebrew name, Yitzḥaq, means “he laughs” or “he will laugh.” Side note – it’s a little bit funny that God told them to name the baby Isaac because that means He already knew they were going to laugh about the perceived impossibility of His plan. Abraham laughed when God first made the promise. Sarah laughed when she heard it for herself.
Sarah laughed again after Isaac was born, but this time for an entirely different reason. “God has made laughter for me; everyone who hears will laugh with me.” The thing that once made Abraham and Sarah laugh because it seemed impossible became the reason Sarah laughed with joy.
God had asked, “Is anything too difficult for the LORD?”
Isaac was the answer.
God has more questions. See Let Me Ask You Something: When God Asks a Direct Question.