Sahih Muslim Book 7, Hadith Number 2976.

Chapter : Excellence of flinging pebbles at Jamrat al-Aqaba on the day of sacrifice (10th of Dhu’l-Hijja) while riding.

Jabir (Allah be pleased with him) reported: I saw Allah’s Apostle (may peace be upon him) flinging pebbles while riding his camel on the Day of Nahr, and he was saying: Learn your rituals (by seeing me performing them), for I do not know whether I would be performing Hajj after this Hajj of mine.