Messenger of Allah (ﷺ) sent Abu 'Ubaidah bin Al-Jarrah (May Allah be pleased with him) to Bahrain to collect (Jizyah). So he returned from Bahrain with wealth. The Ansar got news of it and joined with the Prophet (ﷺ) in the Fajr prayer. When the Prophet (ﷺ) concluded the prayer, they stood in his way. When he saw them, he smiled and said, "I think you have heard about the arrival of Abu 'Ubaidah with something from Bahrain". They said, "Yes! O Messenger of Allah!". He (ﷺ) said, "Rejoice and hope for that which will please you. By Allah, it is not poverty that I fear for you, but I fear that this world will be opened up with its wealth for you as it was opened to those before you; and you vie with one another over it as they did and eventually it will ruin you as it ruined them".

[Al-Bukhari and Muslim].