1. Book of Purification
١۔ كِتَابٌ الطَّهَارَةِ
"Whoever performs Wudu' then let him sniff water in the nose and blow it out, and whoever uses small stones (to remove filth) then make it odd (numbered)." (Using translation from Nasāʾī 88)
سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ «مَنِ اسْتَنْشَقَ فَلْيَسْتَنْثِرْ وَمَنْ اسْتَجْمَرَ فَلْيُوتِرْ»