Rejoice and hope for that which will please you
'Amr bin 'Auf Al-Ansari (May Allah be pleased with him) reported:
Messenger of Allah (may the peace and blessings of Allah be upon him) 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 (may the peace and blessings of Allah be upon him) in the Fajr prayer. When the Prophet (may the peace and blessings of Allah be upon him) 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 (may the peace and blessings of Allah be upon him) 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".
[Muslim].
It was the habit of the Arabs to say: "rejoice" that means your need is fulfilled or will be fulfilled soon, this word has a good impact on the hearts, and develops the sense of optimism.
As for his saying (may the peace and blessings of Allah be upon him): " and hope for that which will please you " means: Demand whatever you want for I will not reject your requests as long as you can meet it. It is recommended to hope in the goodness. You believe in Allah, you hope for richness and fear poverty and this does not contradict the true faith; it is an original aspect of the human nature. Money is likable, it has countless benefits, and it is the base of a well established life.
But behind this saying are wise words which put an end to this hope, and limit it to moderation.
If poverty is harmful, richness also has its own negative effects.
All the goodness lies in being committed to moderation, so that the Muslim has enough means for living but not to violate the limits set by Allah.