Genesis 17:17

17 Then Abraham fell on his face and laughed, and said to himself, "Can a child be born to a man who is a hundred years old? Can Sarah, who is ninety years old, bear a child?"

Genesis 17:17 In-Context

15 God said to Abraham, "As for Sarai your wife, you shall not call her Sarai, but Sarah shall be her name.
16 I will bless her, and moreover I will give you a son by her. I will bless her, and she shall give rise to nations; kings of peoples shall come from her."
17 Then Abraham fell on his face and laughed, and said to himself, "Can a child be born to a man who is a hundred years old? Can Sarah, who is ninety years old, bear a child?"
18 And Abraham said to God, "O that Ishmael might live in your sight!"
19 God said, "No, but your wife Sarah shall bear you a son, and you shall name him Isaac. I will establish my covenant with him as an everlasting covenant for his offspring after him.
New Revised Standard Version Bible, copyright 1989, Division of Christian Education of the National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved.