Musnad Ahmad 472:1

Ya'qub narrated to us, he said: My father narrated to us, from Salih, Ibn Shihab said: 'Urwah ibn al-Zubayr informed me that al-Miswar ibn Makhramah informed him that 'Amr ibn 'Awf—who was an ally of Banu 'Amir ibn Lu'ayy and had witnessed Badr with the Messenger of Allah (peace and blessings of Allah be upon him)—informed him that the Messenger of Allah (peace and blessings of Allah be upon him) sent Abu 'Ubaydah ibn al-Jarrah to Bahrain to bring its jizyah. The Messenger of Allah (peace and blessings of Allah be upon him) had made peace with the people of Bahrain and appointed al-'Ala' ibn al-Hadrami over them. Abu 'Ubaydah arrived with wealth from Bahrain. The Ansar heard of his arrival, so they attended the dawn prayer with the Messenger of Allah (peace and blessings of Allah be upon him). When the Messenger of Allah (peace and blessings of Allah be upon him) finished the dawn prayer, he turned away, and they confronted him. The Messenger of Allah (peace and blessings of Allah be upon him) smiled when he saw them and said: "I think you have heard that Abu 'Ubaydah has come and brought something?" They said: "Yes, O Messenger of Allah." He said: "Then rejoice and hope for what pleases you. By Allah, it is not poverty that I fear for you, but I fear that the world will be spread out for you as it was spread out for those who were before you, so you will compete for it as they competed for it, and it will distract you as it distracted them."