Some argue that the Bible is contradictory concerning the question, “Did Michal have any children?” The argument is that 2 Samuel 6:23 says that Michal had no children, but 2 Samuel 21:8 says that she had five children. However, there is a reasonable explanation that solves this alleged contradiction in the Bible.
And Michal the daughter of Saul had no child to the day of her death.2 Samuel 6:23
But the king took the two sons of Rizpah the daughter of Aiah, whom she bare unto Saul, Armoni and Mephibosheth; and the five sons of Michal the daughter of Saul, whom she brought up for Adriel the son of Barzillai the Meholathite:2 Samuel 21:8 (KJV)
The king took the two sons of Rizpah the daughter of Aiah, whom she bore to Saul, Armoni and Mephibosheth; and the five sons of Merab the daughter of Saul, whom she bore to Adriel the son of Barzillai the Meholathite;2 Samuel 21:18 (ESV)
In 2 Samuel 6:23, some translations say “Merab” instead of “Michal.” For example, the ESV says “Merab,” and there is a footnote that says, “Two Hebrew manuscripts, Septuagint; most Hebrew manuscripts ”Michal”.”
Merab and Michal were both daughters of Saul. The most probable explanation is that the two manuscripts referred to in the ESV translation footnote that say “Merab” instead of “Michal” are correct, and the manuscripts that say “Michal” are the result of a copyist error.
There are some foundational principles that apply to all alleged and apparent contradictions in the Bible. To read more, see Bible Difficulties: Foundational Principles.
To read more answers to alleged and apparent contradictions in the Bible, see “Contradictions” in the Bible Answered.
These books are also excellent resources: