1. Doing a thread on Mother Aisha's age. This is a transcript from @iyad_elbaghdadi's website that I found quite interesting. I'd have linked the page but it no longer exists.

Q: Did Islam's Prophet really marry Aisha when she was 9 years old?

2. I think historians made a mistake, recording Aisha as being born 8 before Hijra when in fact it was 8 before Prophethood. Or perhaps they recorded her birth as 4 after Prophethood when in fact it was 4 before Prophethood. This kind of margin of error (10 years) isn't unusual

3. There's a similar dispute about the age of the Prophet's daughter, Fatima. I think Aisha was closer to 19 when she got married to the Prophet, and here goes my case for saying so. For the following discussion, note that 1 AH = 622 AD. BH = Before Hijra = before 622 AD.

4. Prophethood was in 13 BH = 609 AD. We're talking about people from the 7th century AD (1st century AH). Arabs didn't have a calendar back then. The Hijri calendar was introduced in Umar's caliphate, a few years after the Prophet's death.

5. The first historian of Islam, Ibn Ishaaq, was born in 85 AH and wrote after 132 AH, over a century and a half after the events. How do we know about anything that happened so long back anyway?

6. This was a very important question when it came to establishing the Prophet's traditions (or sayings, or "hadith"). Muslims developed "isnad", an extensive system of authenticated traditions, based upon confirming the chain of narrations.

7. This system of "isnad" was used not only to establish the Prophet's traditions, but also historical events.

The science of "isnad" is one of the great achievements of our civilization, but there's a big glaring hole in it.

8. A lot of effort was spent authenticating the chain of narrations, but not enough on checking the contents of said narrations. I mean, they checked if the chain of narrations was solid but not if the narrations themselves were contradictory.

9. To be fair they developed principles for textual criticism (naqd-al-matn) but it was primitive compared to the elegance of isnad. They also developed this (bad) habit of assuming that if the chain of narrations is correct, the content must be correct too.

10. According to this, if I heard that a pink elephant flew, and the chain of narrations is solid, then it's possible that it really happened.
So let me make a stand here and say that not all hadiths with a "sahih" isnad are in fact authentic.

11. A "sahih" label means their isnad is solid - their content may not be. There could be glaring contradictions.

Aisha's Age is a classic case of this "gaping hole", the chain of narrations seems a-OK, but the contents are so blatantly contradictory.

12. And for Muslims out there, the Qur'an established a test of authenticity - what's contradictory cannot be logically true.

Contradictions
It is relatively well established that Aisha died in 57 AH. Estimates of her age at death range from 63 to 77.

13. There is a narration in Sahih Bukhari attributed to her that says that she was 6 years old when she married the Prophet, and 9 years old when she moved into his house.

14. However, there are narrations both in Bukhari and in other sources (before & after Bukhari) that call this into question. Keep an open mind as you consider the following.

15. Narrations say that Aisha was 10 years younger than her sister Asma, who died in 73 AH at the ripe old age of 100. By simple arithmetic, that means Asma was born in 27 BH, and Aisha in 17 BH.

16. Narrations also say that her father (Abu Bakr) had all his children before the advent of Islam (before 13 BH), which checks out.

Abu Bakr married Aisha's mother when he was 28, in 23 BH. They bore two children. This was an age before birth control.

17. If they got married in 23 BH it seems plausible they had their two children within a few, say 6 years of that date.

Narrations also say that Aisha was the third child to accept Islam, along with Ali (born 23 BH) and Zayd (born 35 BH).

18. That should place her age around theirs (say 18 BH) and not over a decade after theirs (6 BH).

Aisha herself claimed to be the 19th person to enter Islam - impossible if she was born in 6 BH, plausible if in 16 BH or earlier.

19. Other Notes
Arithmetic aside, there are other inconsistencies that scream at you when you read the reports of how the marriage took place.

When the Prophet asked for her hand, her mother objected because Aisha was already engaged to a man from Banu Adi.

20. Details suggest that her earlier engagement happened before 13 BH, which would be impossible if she was born in 6 BH.

Aisha gave an account of a main event that happened in 3 BH (Isra & Miraj). Would be impossible if she was 3 at the time.

21. Aisha narrates in Bukhari that when a certain chapter of the Qur'an was revealed, she was "playing, as an adolescent"; the chapter in question was revealed between 10 BH and 8 BH. This again suggest that she was born between 20 BH and 18 BH.

22. Aisha also gave a detailed, mature account of events of the Hijra itself (1 AH). Implausible if she was only six.

In 3 AH a major battle (called the Battle of Uhud) erupted near Medina.

23. The Prophet sent home anyone under 15 years of age, but Aisha played a role in the battle, carrying water from Medina to the soldiers on the battle field. At nine years old?

24. In fact, there are indications that Aisha was on the scene at the Battle of Badr, in 2 AH, which would be extremely unlikely if she was a child of 7 or 8 years.

25. https://twitter.com/Gowhar_/status/1250404273831194626?s=20