1. Purification
١۔ كِتَابُ الطَّهَارَةِ
"Water is for Water." [1] [1] That is, water for peforming Ghusl is obligatory when the ejaculation of water (semen) occurs. (Using translation from Nasāʾī 199)
عَنِ النَّبِيِّ ﷺ قَالَ «الْمَاءُ مِنَ الْمَاءِ»