Is it permissible to condition the agency contract upon a future event?
General Chapter
Al-Mughni
Book of Agency
Primary text
Conditioning the agency contract upon a future occurrence is permissible. Examples include saying, "If the pilgrim arrives, sell this food," or "When winter comes, buy charcoal for us," or "If my family asks you for something, give it to them." This view is held by Abu Hanifa. The underlying rationale is that the Prophet Muhammad (PBUH) appointed a sequence of commanders: "Your commander is Zayd, and if he is killed, then Ja'far, and if he is killed, then Abdullah ibn Rawahah," which is analogous. Also, since the contract establishes the ruling of permissibility of action for the agent, it should be valid, similar to saying, "You are my agent to sell my slave when the pilgrim arrives."
Supporting text
Imam Shafi'i holds that conditioning the agency is invalid. However, if the agent acts based on the conditioned statement, the transaction performed by the agent is valid due to the existence of permission. If the agency was for a fee (Ja'l), the specified fee is voided, but the agent is entitled to a fair wage (Ujr al-Mithl). This is because agency is a contract that grants the authority to act during one's lifetime, thus resembling a sale.