Narrated Abu Huraira: The Prophet said, "Whoever performs ablution should clean his nose with water by putting the water in it and then blowing it out, and whoever cleans his private parts with stones should do it with odd number of stones."
Hadith ReferenceSahih Bukhari / The Book of Wudu (Ablution) / Hadith: 161
Hadith Gradingمحدثین:أحاديث صحيح البخاريّ كلّها صحيحة