It was narrated that Salamah bin Qais said to me:
The Messenger of Allah said to me: 'When you perform ablution, clean your nose, and when you use pebbles to clean yourself after defecating, use an odd number.'" (FR)
English reference (FR): Vol. 1, Book 1, Hadith 406 (FR)
Arabic reference (FR): Book 1, Hadith 440 (FR)