The answer is: She laughed

Genesis 18:12 - Sarah laughed when she heard she would have a child because she and Abraham were very old. This laughter became significant when Isaac, whose name means "he laughs," was born.

Sarah's laughter is one of those moments in scripture that captures the mix of disbelief and joy that can come with unexpected blessings. Imagine being well past the ages of parenthood and hearing a promise that you'd be holding a baby—laughter is perhaps the most appropriate response! This moment also highlights her struggle with faith and vulnerability. It’s a welcoming reminder that even the most steadfast of figures can wave the flag of doubt, letting us know it's human to experience such feelings.

What's even more intriguing is the dual meaning of Isaac's name "he laughs." This resonance plays through the stories that unfold later, representing not only joy but the profound reversal of circumstances. During a time when many would expect only end to their family lineage, God flips the script entirely! Many biblical names carry deep symbolism, like Abraham, which means "father of many nations."

Furthermore, Sarah's laughter directly ties to the broader theme of divine promises. Biblical echoes vibrate throughout the text, gently nudging us to remember that doubting isn’t shunning faith. The narratives remind us that divine plans teem with humor and splendid surprises! It’s not unusual to find ourselves chuckling amid struggles, just like Sarah, and therein lies a beautifully shared human experience. That laughter wasn’t just hers; it became a legacy of joyous anticipation.