[Machine] On the authority of the Prophet ﷺ, regarding a man who wakes up and sees wetness without remembering having a dream, he said, "Let him perform Ghusl (ritual bath) if he sees a wet dream but does not see any wetness, then there is no obligation for him to perform Ghusl."  

عَنِ النَّبِيِّ ﷺ فِي الرَّجُلِ يَسْتَيْقِظُ فَيَرَى بَلَلًا وَلَمْ يَذْكُرِ احْتِلَامًا قَالَ «لِيَغْتَسِلْ فَإِنْ رَأَى احْتِلَامًا وَلَمْ يَرَ بَلَلًا فَلَا غُسْلَ عَلَيْهِ»