Narrated by:'Ali said
It was narrated that 'Ali said:"The Messenger of Allah was asked about prostatic fluid and he said: 'For that ablution (is necessary), and for semen, bath is necessary.'"
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا هُشَيْمٌ، عَنْ يَزِيدَ بْنِ أَبِي زِيَادٍ، عَنْ عَبْدِ الرَّحْمَنِ بْنِ أَبِي لَيْلَى، عَنْ عَلِيٍّ، قَالَ سُئِلَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ عَنِ الْمَذْىِ فَقَالَ " فِيهِ الْوُضُوءُ وَفِي الْمَنِيِّ الْغُسْلُ " .
IbnMaja
The Book of Purification and its Sunnah • Hadith 504