Musnad Ahmad 201:1

Waki’ narrated to us, from ‘Amr ibn Hassan—meaning al-Musalli—who said: al-Mughirah ibn ‘Abdullah al-Yashkuri narrated to us, from his father, who said: I entered the Mosque of Kufa when its mosque was first built, and it was among the date sellers at that time, and its walls were made of soft stone. There was a man speaking to the people. He said: "The Hajj of the Messenger of Allah (peace and blessings of Allah be upon him), the Farewell Pilgrimage, reached me. So I followed a riding camel of mine, then I went out until I sat for him on the road to ‘Arafah—or I stood for him on the road to ‘Arafah." He said: "Then a caravan appeared, and I recognized the Messenger of Allah (peace and blessings of Allah be upon him) among them by his description. A man in front of him said: 'Clear the way for the caravan.' The Prophet (peace and blessings of Allah be upon him) said: 'Woe to him, what does he want?'" He said: "I drew near to him until the heads of the two camels were side by side. I said: 'O Messenger of Allah, guide me to a deed that will cause me to enter Paradise and save me from the Fire.' He said: 'Excellent, excellent. If you have been brief in the sermon, you have been eloquent in the question. Understand, then: Worship Allah, the Mighty and Majestic, and do not associate anything with Him, establish the prayer, pay the zakat, perform Hajj to the House, and fast Ramadan. Clear the way for the caravan.'"