ENOfficial
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: sunnah.com
Other translations
Arabic
وَقَالَ ابْنُ عَبَّاسٍ: إِنَّمَا الْمَاءُ مِنَ الْمَاءِ فِي الِاحْتِلَامِ. رَوَاهُ التِّرْمِذِيُّ وَلَمْ أَجِدْهُ فِي الصَّحِيحَيْنِ
sunnah.com