أَخْبَرَنَا مُحَمَّدُ بْنُ حَاتِمٍ قَالَ: حَدَّثَنَا عَبِيدَةُ قَالَ: حَدَّثَنَا سُلَيْمَانُ الأَعْمَشُ عَنْ حَبِيبِ بْنِ أَبِي ثَابِتٍ عَنْ سَعِيدِ بْنِ جُبَيْرٍ عَنِ ابْنِ عَبَّاسٍ عَنْ عَلِيٍّ رَضِيَ اللَّهُ عَنْهُ قَالَ: كُنْتُ رَجُلاً مَذَّاءً فَأَمَرْتُ رَجُلاً فَسَأَلَ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَقَالَ: «فِيهِ الْوُضُوءُ».

It was narrated that 'Ali, may Allah be please with him, said: "I was a man who emotted a great deal of Madhi. I told a man to ask the Prophet (PBUH) (about that) and he said: 'Wudu' (is required) for that." Translation Not Available

Book reference: Sunan An Nisai Book 4 Hadith 436
Web reference: Sunan An Nisai Volume 1 Book 4 Hadith 437