When anyone wipes himself with pebbles (after answering the call of nature) he should do this odd number of times.
Sahih Muslim Book 2, Hadith 32
← Previous Hadith The Apostle of Allah (ﷺ) said. When any one of you awakes up from sleep and performs ablution, he must clean his nose three times, for the devil spends the night in the interior of his nose.

Sahih Muslim Book 2, Hadith 31 Next Hadith → I came to 'A'isha, the wife of the Prophet (ﷺ), on the day when Sa'db. Abi Waqqas died. 'Abd al-Rahman b. Abu Bakr also came there and he performed ablution in her presence. She (Hadrat 'A'isha) said: Abd al-Rahman, complete the ablution as I heard the Allah's Messenger (ﷺ) say: Woe to the heels because of hell-fire.

Sahih Muslim Book 2, Hadith 33