Hiring/Renting: Being Hired for a Task Without a Formula

Practical Laws of Islam as per the teachings of Ayatullah Sistani

Ruling 2188

If a person wishes to be hired for a particular task without saying a formula, the hire agreement is valid the moment he engages himself in that task.

-Ayatullah Sistani, Practical Laws of Islam, Hiring/Renting (Ijarah)