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Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī

Allah will make the Mahdī righteous overnight, hence his title, the Mahdī (the One Rightly Guided)

ibnmajah:4085 – ʿUthmān b. Abū Shaybah > Abū Dāwud al-Ḥafarī > Yāsīn > Ibrāhīm b. Muḥammad Ibn al-Ḥanafiyyah from his father > ʿAlī

"Mahdi is one of us, the people of the Household. Allah will rectify him in a single night."  

ابن ماجة:٤٠٨٥ – حَدَّثَنَا عُثْمَانُ بْنُ أَبِي شَيْبَةَ حَدَّثَنَا أَبُو دَاوُدَ الْحَفَرِيُّ حَدَّثَنَا يَاسِينُ عَنْ إِبْرَاهِيمَ بْنِ مُحَمَّدِ ابْنِ الْحَنَفِيَّةِ عَنْ أَبِيهِ عَنْ عَلِيٍّ قَالَ

قَالَ رَسُولُ اللَّهِ ﷺ الْمَهْدِيُّ مِنَّا أَهْلَ الْبَيْتِ يُصْلِحُهُ اللَّهُ فِي لَيْلَةٍ  

See similar narrations below:

Collected by Aḥmad, Suyūṭī
ahmad:645 – Faḍl b. Dukayn > Yāsīn al-ʿIjlī > Ibrāhīm b. Muḥammad Ibn al-Ḥanafiyyah from his father > ʿAlī

The Messenger of Allah ﷺ said: “The Mahdi is one of us’ Ahlal-Bait (the prophet’s family) and Allah will prepare him in one night”.  

أحمد:٦٤٥ – حَدَّثَنَا فَضْلُ بْنُ دُكَيْنٍ حَدَّثَنَا يَاسِينُ الْعِجْلِيُّ عَنْ إِبْرَاهِيمَ بْنِ مُحَمَّدِ ابْنِ الْحَنَفِيَّةِ عَنْ أَبِيهِ عَنْ عَلِيٍّ قَالَ

قَالَ رَسُولُ اللهِ ﷺ الْمَهْدِيُّ مِنَّا أَهْلَ الْبَيْتِ يُصْلِحُهُ اللهُ فِي لَيْلَةٍ