Now Abraham and Sarah were old and well stricken in age; and it ceased to be with Sarah after the manner of women. It ceased to be with Sarah after the manner of women - And consequently, naturally speaking, conception could not take place; therefore if she have a son it must be in a supernatural or miraculous way.
Related Commentaries of Genesis 18:11
Genesis 18:11
11 Now Abraham and Sarah were old and well stricken in age; and it ceased to be with Sarah after the manner of women.