Ṣaḥīḥ al-Bukhārī & Ṣaḥīḥ Muslim

‘Uqbah ibn ‘Āmir (may Allah be pleased with him) reported: One day, the Messenger of Allah (may Allah’s peace and blessings be upon him) went out and supplicated for the martyrs of the battle of Uhud eight years after (their death), as if he was bidding farewell to the living and the dead.

He then ascended the pulpit and said: "I shall be the precursor before you; I am a witness for you (before Allah), your promised place to meet me will be the Cistern of Al-Kawthar; and I am (now) looking at it from this place of mine. I am not afraid that you will worship others besides Allah, but I am afraid that the worldly life will tempt you and cause you to compete with each other for it." That was my last sight of the Prophet (may Allah’s peace and blessings be upon him).

According to another narration: “…but I am afraid that you will compete over the worldly life, whereupon you will kill each other for it and perish as past nations did.” ‘Uqbah (may Allah be pleased with him) added: “This was the last time I saw the Prophet (may Allah's peace and blessings be upon him) on the pulpit.” According to a third narration, the Prophet (may Allah's peace and blessings be upon him) said: “I will be there ahead of you, and I will be your witness. By Allah, I can see my Cistern now.

I am given the keys to the treasures of the earth, or the keys to the earth. By Allah, I do not fear that you will associate others with Allah after I am gone, but I fear that you will compete with one another for them (the treasures of the earth).”