Sayyiduna Uqbah bin Amir al-Juhani (may Allah be pleased with him) narrates: The last sermon that the Prophet (peace and blessings of Allah be upon him) gave us was that he first offered the funeral prayer for the martyrs of Uhud, then he ascended the pulpit and praised and glorified Allah, then said: "Indeed, I will precede you and I will be a witness over you, and at this moment I am standing at my place and looking at my Hawd (cistern). By Allah! I do not fear that you will commit shirk after me, but I have been shown that the keys to the treasures of the earth have been given to me, so I fear regarding you that you will become inclined towards the world."
Hadith Referenceصحیح ابن حبان / كتاب الزكاة / 3224
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح - «الأحكام» (ص 107): ق.فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده صحيح على شرط مسلم