Sahih Muslim Book 42, Hadith Number 7065.
Chapter : Not known.
‘Amr b. ‘Auf, who was an ally of Banu ‘Amir b. Luwayy (and he was one amongst them) who participated in Badr along with Allah’s Messenger (way peace be upon him) reported that, Allah’s Messenger (may peace be upon him) sent Abu Ubaida b. Jarrah to Bahrain for collecting Jizya and Allah’s Messenger (may peace be upon him) had made a truce with the people of Bahrain and had appointed ‘Ala’ b. Hadrami and Abu Ubaida (for this purpose). They came with wealth from Bahrain and the Ansar beard about the arrival of Abu Ubaida and they had observed the dawn prayer along with Allah’s Messenger (may peace be upon him), and when Allah’s Messenger (may peace be upon him) had finished the prayer they (the Ansar) came before him and Allah’s Messenger (may peace be upon him) smiled as he saw them and then said: I think you have heard about the arrival of Abu Ubaida with goods from Bahrain. They said: Allah’s Messenger, yes, it is so. Thereupon he said: Be happy and be hopeful of that what gives you delight. By Allah, it is not the poverty about which I fear in regard to you but I am afraid in your case that (the worldly) riches way be given to you as were given to those who had gone before you and you begin to vie with one another for them as they vied for them and these may destroy you as these destroyed them.