Mishkat al-MasabihChapter 3Hadith 400
Full Sharh — Mishkat al-Masabih 400
وَقَالَ ابْنُ عَبَّاسٍ: إِنَّمَا الْمَاءُ مِنَ الْمَاءِ فِي الِاحْتِلَامِ. رَوَاهُ التِّرْمِذِيُّ وَلَمْ أَجِدْهُ فِي الصَّحِيحَيْنِ
English Translation
Ibn ‘Abbas said that "Water is necessary only when there is an emission” applies to a dream. Tirmidhi transmitted it, but I have not found it in the two Sahihs.
Source
Mishkat al-Masabih(مشكاة المصابيح)
Purification
Hadith Number
400