The Messenger of Allah ﷺ said, "When you perform ablution, blow water out of your nose, and when you clean yourself with stones, use an odd number."
حدثنا سفيان بن عيينة عن منصور عن هلال بن يساف
قال رسول الله ﷺ إذا توضأت فانتثر وإذا استجمرت فأوتر
Its isnad is sahih, it has already appeared at 18719.