10 And he said, I will certainly come back to you in the spring, and Sarah your wife will have a son. And his words came to the ears of Sarah who was at the back of the tent-door. 11 Now Abraham and Sarah were very old, and Sarah was past the time for giving birth. 12 And Sarah, laughing to herself, said, Now that I am used up am I still to have pleasure, my husband himself being old? 13 And the Lord said, Why was Sarah laughing and saying, Is it possible for me, being old, to give birth to a child? 14 Is there any wonder which the Lord is not able to do? At the time I said, in the spring, I will come back to you, and Sarah will have a child. 15 Then Sarah said, I was not laughing; for she was full of fear. And he said, No, but you were laughing.
Matthew Henry's Commentary on Genesis 18:10-15
Commentary on Genesis 18:9-15
(Read Genesis 18:9-15)
Where is Sarah thy wife? was asked. Note the answer, In the tent. Just at hand, in her proper place, occupied in her household concerns. There is nothing got by gadding. Those are most likely to receive comfort from God and his promises, who are in their proper place, and in the way of their duty, 17; but He who searches the heart, saw that the one sprung from unbelief, and the other from faith. She denied that she had laughed. One sin commonly brings in another, and it is not likely we shall strictly keep to truth, when we question the Divine truth. But whom the Lord loves he will rebuke, convict, silence, and bring to repentance, and if they sin before him.