Hadithcore
Mishkat al-Masabih, 311

‘Ali said:

I asked the Prophet (ﷺ) about prostatic fluid and he replied, “For prostatic fluid ablution is necessary, but for seminal emission washing.” Tirmidhi transmitted it.

وَعَن عَلِيٍّ قَالَ: سَأَلَتْ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ مَنْ الْمَذْيِ فَقَالَ: «مِنَ الْمَذْيِ الْوُضُوءُ وَمِنَ الْمَنِيِّ الْغسْل» . رَوَاهُ التِّرْمِذِيّ

References1 variant
In-Book Reference
Book 3, Hadith 29