Hiring/Renting: Subletting Something Other Than a House, Shop, or Ship
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 2192
If a person rents something other than a house, shop, or ship – for example, he rents some land – and the owner does not stipulate a condition that only he must use it, then, if he gives it on rent for an amount that is higher than what he has rented it for, the validity of the rental agreement is problematic (maḥall al‑ishkāl) [i.e. based on obligatory precaution, it is not valid].[1]
-Ayatullah Sistani, Practical Laws of Islam, Hiring/Renting (Ijarah)
1
Ruling 2091 provides further clarification of this term: it refers to someone who spends his wealth in futile ways.