Musnad Ahmad

Hazrat Amr bin Auf (may Allah be pleased with him), who was among the participants of the Battle of Badr, narrates that the Noble Prophet (peace and blessings be upon him) once sent Hazrat Abu Ubaidah bin Jarrah (may Allah be pleased with him) to Bahrain so that he could collect the jizya from there. The Noble Prophet (peace and blessings be upon him) had made a peace agreement with the people of Bahrain and had appointed Hazrat Alaa bin Hadrami (may Allah be pleased with him) as their leader. Thus, Abu Ubaidah (may Allah be pleased with him) brought wealth from Bahrain... Then the narrator mentioned the entire hadith. It is narrated from Hazrat Miswar bin Makhramah (may Allah be pleased with him) that Abu Ubaidah (may Allah be pleased with him) brought wealth from Bahrain. When the Ansar learned of his arrival, they presented themselves before the Noble Prophet (peace and blessings be upon him) at the time of the Fajr prayer. When the Noble Prophet (peace and blessings be upon him) finished the Fajr prayer, they came before him. The Noble Prophet (peace and blessings be upon him) smiled upon seeing them and said, "Perhaps you have heard of Abu Ubaidah's return and that he has brought something?" They replied, "Yes, O Messenger of Allah!" The Noble Prophet (peace and blessings be upon him) said, "Rejoice and hope for that which will make you happy. By Allah, I do not fear poverty for you, but I fear that the world will be opened up for you as it was opened up for those before you, and you will compete in it as they competed."