Basically, when Saudi Arabia found oil in it's territory, Jordan decided it was going to look for oil.
It instead found it was sitting on several water aquifers.
These are two of the most water-scarce natio ns on earth.
So, to find water, something you need to survive, in decent qualities in your terrtory, while it wont make much money selling it to the main buyers of oil, it will instead mean you can sell water to everyone around you and still ,ake a lot of money. In areas like that, having water sources is far more powerful than having oil.