Ruling 2244 — Reward (Juʿālah)

The worker can choose to leave the task unfinished. However, if leaving the task unfinished would cause harm to the offeror or someone for whom the task is being performed, he must complete it. For example, if someone says, ‘Whoever operates on my eye, I will give him such and such amount’, and a surgeon starts operating on his eye, in the event that were he to leave the operation unfinished it would lead to the offeror having a defective eye, he must complete the operation.