Hazrat Amr bin Auf (may Allah be pleased with him), who was an ally of Banu Amir bin Lu'ayy and participated in the Battle of Badr, narrated that the Messenger of Allah (peace and blessings be upon him) sent Abu Ubaidah bin Jarrah (may Allah be pleased with him) to Bahrain to collect the jizya. The Prophet (peace and blessings be upon him) had made a peace agreement with the people of Bahrain and had appointed Alaa bin Hadrami (may Allah be pleased with him) as their governor. When Abu Ubaidah (may Allah be pleased with him) returned with the wealth from Bahrain, the Ansar came to know that Abu Ubaidah had arrived. So, all the people performed the Fajr prayer with the Prophet (peace and blessings be upon him). When the Prophet (peace and blessings be upon him) finished the prayer, the people came before him. The Prophet (peace and blessings be upon him) smiled upon seeing them and said, "I think you have heard that Abu Ubaidah has brought something?" The Ansar (may Allah be pleased with them) replied, "Yes, O Messenger of Allah!" The Prophet (peace and blessings be upon him) said, "Receive glad tidings, and hope for that which will make you happy. But by Allah! I do not fear poverty and need for you. If I fear anything, it is that the doors of the world will be opened for you as they were opened for those before you, and you will begin to compete with one another as they did, and this rivalry will destroy you just as it destroyed those before you."