Can store water.
The empty space in porous rocks can store liquid or gas.
Reservoir rocks are rocks that have the ability to store fluids inside their pores, so that the fluids (water, oil, and gas) can be accumulated.
American Association of Petroleum Geologists, Reservoir, 2019
So water is one of the fluids that these rocks can store. However this was portrayed in the Quran 1400 years before it was discovered.
[Quran 2:74] Then after that your hearts hardened like rocks, or even harder. For there are some rocks from which rivers gush out, and others that crack and water comes out from them, and others that descend in awe of Allah. Allah is not unaware of what you do.
How could an illiterate man who lived 1400 years ago have known that rocks can store water?
For "others that crack and water comes out from them" see Rocks Crack.
For "others that descend in awe of Allah" see Subduction.