From Sahih Muslim (Hadith 5977):
Uqba b. 'Amir reported Allah's Messenger (ﷺ) as saying:Allah's Messenger offered prayer over those who had fallen matyrs at Uhud. He then climbed the pulpit as if someone is saying good-bye to the living and the dead, and then said: I shall be there as your predecesor on the Cistern before you, and it is as wide as the distance between Aila and Juhfa (Aila is at the top of the gulf of 'Aqaba). I am not afraid that you would associate anything with Allah after me, but I am afraid that you may be (allured) by the world and (vie) with one another (in possessing material wealth) and begin killing one another, and you would be destroyed as were destroyed those who had gone before you. 'Uqba said that that was the last occasion that he saw Allah's Massenger on the pulpit
Reference: Muslim 5977