The Story of A Woman Interjecting And Correcting Umar (رضي الله عنه) On The Issue of Mahr Is Unauthentic!

The story goes (as quoted in umar-ibn-khattab.blogspot.com/2011/02/women-knew-religion-more-than-umar.html?m=1)

One day Caliph Umar during the course of his sermon to the people, said: “If any one marries and fixes a mehr (dowry) for more than 400 dirhams for his wife, I will inflict the prescribed punishment on him and will deposit the excess amount in the Baitu’l-Mal (Public Treasury).”

A woman from the audience called out: “Umar! Is what you say more acceptable or Allah’s ordinance? Does not Allah Almighty say: ‘And if you wish to have (one) wife in place of another and you have given one of them a heap of gold, then take not from it anything.’” (4:20)

Having heard this verse and the retort of the woman, Umar said: “You have better knowledge of fiqh and problems than Umar, all of you, including even the women observing purdah sitting in their homes.”

Then Umar again mounted the pulpit and said: “Although I have forbidden you to give more than 400 dirhams as dowry to your wives, I now permit you to give as much as you like beyond the appointed limit. There is no harm in it.”

This hadith shows that Caliph Umar was not well versed in the Qur’an and jurisprudence. Otherwise, he would not have said something so obviously incorrect that he could be silenced by an informed woman

References:
1. Jalalu’d-din Suyuti in his Tafsir-e-Durru’l-Mansur, vol. II, p.133;
2. Ibn Kathir in his Commentary, vol.I, p.468;
3. Jarullah Zamakhshari in his Tafsir-e-Kashshaf, vol.I, p.357;
4. Fazil Nishapuri in his Tafsir-Gharibu’l Qur’an, vol.I, in connection with the sura Nisa (The Women) of the Holy Qur’an;
5. Qartabi in his Tafsir, vol.V, p.99;
6. Ibn Maja’ Qazwini in his Sunan, vol.I; Asadi in Hashiyya-e-Sunan, vol.I, p.583;
7. Baihaqi in his Sunan, vol.VII, p.233;
8. Qastalani in his Irshadu’s-Sari-Sharh-e-Sahih Bukhari, vol.VIII, p.57;
9. Muttaqi Hindi in his Kanzu’l-’Ummal, vol.VIII, p. 298;
10. Hakim Nishapuri in his Mustadrak, vol.II, p.177;
11. Abu Bakr Baglani in his Tamhid, p.199;
12. Ajluni in his Kashfu’l-Khufa’, vol.I, p.270;
13. Qazi Shukani in Futuhu’l-Qadir, vol.I,P.407;
14. Dhahabi in his Takhlis-e-Mustadrak;
15. Ibn Abi’l-Hadid in his Sharh-e-Nahju’l-Balagha, vol.I, p.61 and vol.VII, p.96;

16. Hamidi in his Jam’-e-Bainu’s-Sahihain;
17. Faqih Wasiti Ibn Maghazili Shafi’i in his Manaqib;
18. Ibn Athir in his Nihaya.
End quote from the website.
Note: Loads of references do not make a story authentic.
This story is extremely weak and none of its routes are Sahih or Hasan.
See the research here in Arabic:
The authentic Hadith is as follows:
It was narrated that:
Abu Ajfa As-Sulami said: “Umar bin Khattab said: ‘Do not go to extremes with regard to the dowries of women, for if that were a sign of honor and dignity in this world or a sign of Taqwa before Allah, then Muhammad (ﷺ) would have done that before you. But he did not give any of his wives and none of his daughters were given more than twelve uqiyyah. A man may increase dowry until he feels resentment against her and says: “You cost me everything I own,” or, “You caused me a great deal of hardship.”’”
Sunan Ibn Majah 1886.
Abu Al-Ajfa (As-Salami) said:
“Umar bin Al-Khattab said: ‘Do not exaggerate in the dowries of women. If doing so was honorable in the world or Taqwa before Allah then Allah’s Prophet would have been the first of you to do it. I do not know of the Messenger of Allah marrying any of his women, nor giving any of his daughters in marriage, for more than twelve Uqiyah.”
Sunan At-Tirmidhi 1114.  (Also in Suna. An-Nasai and Sunan Abi Dawud) [Hasan Sahih accordion to Imam At-Tirmidhi. ]
Summary:
Umar (رضي الله عنه) did reprimand people for being extravagant in Mahr but no one is authentically reported to have objected to his advise.
-Abu Muaaz Mohammed Manna.