In the 12th verse of Surah Mujādilah, we read: “O you who have faith! When you talk secretly to the Apostle, offer a charity before your secret talk. That is better for you and purer. But if you cannot afford [to make the offering], then Allah is indeed all-forgiving, all-merciful.”
In the 12th verse of Surah Mujādilah, we read: “O you who have faith! When you talk secretly to the Apostle, offer a charity before your secret talk. That is better for you and purer. But if you cannot afford [to make the offering], then Allah is indeed all-forgiving, all-merciful.” The majority of Shia and Sunni commentators have written that: The only individual who acted upon the verse of Najwā was Imam ‘Ali (‘a). Ṭabarsī has narrated a tradition from the Imam (‘a) where he said: There is a verse in the Quran that no one before me or after me acted upon. I had one dinar which I changed in to ten dirhams and whenever I wanted to speak (in private) with the Prophet (ṣ), I would give one dirham of it in charity.
A similar tradition has been narrated by Shawkānī from ‘Abd al-Razzāq, Ibn al-Mundhar, Ibn Abī Ḥātam, and Ibn Mardawīyah. Fakhr Rāzī has also narrated a tradition which mentions that the aforementioned verse was only acted upon by Imam ‘Ali (‘a) and he has narrated this tradition from a group of scholars who narrated it from Ibn ‘Abbās. Durr al-Manthūr also has narrated numerous traditions in regards to this verse and they all mention the same issue as the traditions above.
In the Tafsīr of Rūḥ al-Bayān from ‘Abdullah, the son of ‘Umar ibn Khaṭṭāb, it has been narrated that he said: ‘Ali had three virtues, which if I had only one of them, it would have been more valuable to me than red haired camels (this was a famous saying amongst the Arabs for something of the greatest value). The first was his marriage with Fatimah, the second is how he was given the flag on the day of Khaybar, and the third is the verse of Najwā. The story of how Imam ‘Ali (‘a) acted upon the verse of Najwā has been narrated in the majority of the books of commentary and tradition and it is something extremely well known amongst the Muslim scholars and further explanation at this point would simply be considered redundant.
 Surah Mujādilah, verse 12: «یا أَیُّهَا الَّذِینَ آمَنُوا إِذا ناجَیْتُمُ الرَّسُولَ فَقَدِّمُوا بَیْنَ یَدَیْ نَجْواکُمْ صَدَقَةً ذالِکَ خَیْرٌ لَکُمْ وَ أَطْهَرُ فَإِنْ لَمْ تَجِدُوا فَإِنَّ اللهَ غَفُورٌ رَحِیمٌ »  «آیَةٌ مِنْ کِتابِ اللّهِ لَمْ یَعْمَلْ بِها أَحَدٌ قَبْلِى، وَ لایَعْمَلُ بِها أَحَدٌ بَعْدِى کانَ لِى دِینارٌ فَصَرَفْتُهُ بِعَشَرَةِ دَراهِمَ فَکُنْتُ إِذا جِئْتُ إِلَى النَّبِى(صلى الله علیه وآله) تَصَدَّقْتُ بِدِرْهَم»  Tafsīr al-bayān fī tafsīr al-qurān, vol. 1, p. 375; Sayyid Quṭb has also mentioned this tradition in his Fī Ḍilāl al-Qurān, vol. 8, p. 21.  Tafsīr fakhr rāzī, vol. 29, p. 271.  Durr al-manthūr, vol. 6, p. 185.  Tafsīr rūḥ al-bayān, vol. 9, p. 402 (this tradition is narrated by Ṭabarsī in his Majma' al-bayān, Zamakhsharī in his Kashshāf, Qurṭubī in his Tafsīr Jāmi' under the aforementioned verse, etc…): «کانَ لِعَلِىٍّ(علیه السلام) ثَلاثٌ، لَوْ کانَتْ لِى واحِدَةٌ مِنْهُنَّ کانَتْ أَحَبَّ إِلَىَّ مِنْ حُمُرِ النَّعَمِ: تَزْوِیجُهُ فاطِمَةَ(علیها السلام)، وَ إِعْطائُهُ الرّایَةَ یَوْمَ خَیْبَرَ، وَ آیَةُ النَّجْوى!»  Taken from the text: Tafsīr nemūneh, Ayatullah Makarem Shirazi, Dār al-Kutub al-Islāmīyah, 27th Edition, vol. 23, p. 461.