Contradiction with Genesis 16:1-2
This verse explains how Sarah, being barren, suggests that Abraham have a child with Hagar, which contradicts Genesis 21:2 where Sarah bears a son, Isaac, despite her previous barrenness.
Genesis 16:1-2: Now Sarai Abram's wife bare him no children: and she had an handmaid, an Egyptian, whose name [was] Hagar.
Contradiction with Genesis 18:11-12
These verses detail Sarah's disbelief and laughter at the promise of having a child in her old age, which contrasts with Genesis 21:2 where she successfully gives birth to Isaac.
Genesis 18:11-12: Now Abraham and Sarah [were] old [and] well stricken in age; [and] it ceased to be with Sarah after the manner of women.
Contradiction with Genesis 17:17
Abraham expresses doubt about having a child at his and Sarah's advanced ages, questioning if a child could be born to a 100-year-old man and a 90-year-old woman, which contradicts the fact of Isaac's birth in Genesis 21:2.
Genesis 17:17: Then Abraham fell upon his face, and laughed, and said in his heart, Shall [a child] be born unto him that is an hundred years old? and shall Sarah, that is ninety years old, bear?
Contradiction with Genesis 11:30
This verse explicitly states that Sarah was barren and had no child, which contrasts with Genesis 21:2 where she births Isaac.
Genesis 11:30: But Sarai was barren; she [had] no child.
Contradiction with Judges 13:2-3
While not directly related to Sarah and Isaac, these verses describe Manoah's wife as initially barren before giving birth to Samson, similar to but distinct from Sarah's story, emphasizing the theme of barrenness overturned by divine intervention as a rare event.
Judges 13:2-3: And there was a certain man of Zorah, of the family of the Danites, whose name [was] Manoah; and his wife [was] barren, and bare not.
Paradox #1
In Genesis, God promises Abraham and Sarah a son even though they are very old. The contradiction some point out is that Sarah's ability to have a child at such an advanced age challenges natural biological laws. Additionally, earlier chapters in Genesis mention how old they were, raising questions about the consistency of timelines in the narrative.